<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03301753</url>
  </required_header>
  <id_info>
    <org_study_id>140M50203</org_study_id>
    <secondary_id>R01HD080444</secondary_id>
    <nct_id>NCT03301753</nct_id>
  </id_info>
  <brief_title>Maternal Obesity, Breast Milk Composition, and Infant Growth</brief_title>
  <acronym>(MILK)</acronym>
  <official_title>Maternal Obesity, Breast Milk Composition, and Infant Growth</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>University of Minnesota</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)</agency>
      <agency_class>NIH</agency_class>
    </collaborator>
    <collaborator>
      <agency>HealthPartners Institute</agency>
      <agency_class>Other</agency_class>
    </collaborator>
    <collaborator>
      <agency>University of Oklahoma</agency>
      <agency_class>Other</agency_class>
    </collaborator>
  </sponsors>
  <source>University of Minnesota</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      Today the majority of pregnant women in the United States are either overweight or obese at&#xD;
      conception with their offspring having greater adiposity at birth, a 2-fold greater risk of&#xD;
      later obesity, and neonatal insulin resistance. It was long thought that breast milk&#xD;
      composition was fairly uniform among women, having been optimized through evolutionary time&#xD;
      to provide adequate sole nutrition for the growing infant regardless of the environmental&#xD;
      circumstances. However, recent evidence shows that breast milk is a highly complex fluid with&#xD;
      significant inter-individual variation in hormonal and cytokine concentrations. Pervasive&#xD;
      maternal obesity is an evolutionarily novel condition for the human species but little effort&#xD;
      has yet been made to systematically examine how this novel condition is associated with&#xD;
      breast milk adipose-tissue derived hormone and cytokine (adipocytokine) variation, or whether&#xD;
      that variation relates to infant metabolic status. The objective of this study is to&#xD;
      comprehensively assess the &quot;lactational programming&quot; hypothesis, that is, whether or not&#xD;
      recently documented variation in breast-milk composition is related to both maternal&#xD;
      adiposity and to infant metabolic status. The central hypothesis is that a graded,&#xD;
      dose-response relationship between maternal adiposity and adipocytokine concentrations in&#xD;
      breast milk exists and that milk adipocytokine concentrations are associated with altered&#xD;
      body composition in their exclusively breast-fed offspring. The results of the study will be&#xD;
      used to design interventions to reduce maternal weight during pregnancy and lactation and to&#xD;
      augment lactation education materials to focus on the needs of obese breast-feeding women.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      General Study Design A prospective observational pregnancy cohort of 360 non-diabetic&#xD;
      mothers, who exclusively breastfeed their infants to at least 1 month post-partum, will be&#xD;
      recruited in the second trimester of pregnancy, across a wide range of maternal pre-pregnancy&#xD;
      BMI, with equal numbers of normal weight, overweight, and obese women. The women will be&#xD;
      recruited at two study centers (University of Oklahoma Health Sciences Center in Oklahoma&#xD;
      City, OK and Health Partners Research Foundation in Saint Paul/Minneapolis, MN), with&#xD;
      maternal and infant diet, body composition and metabolic health followed prospectively at 1,&#xD;
      3 and 6-months post-partum in Specific Aims 1 and 2. In Specific Aim 3, a subset of 60 of&#xD;
      these mother/infant dyads &quot;Mothers in Focus&quot; (30 OB and 30 NW mothers) will be recruited for&#xD;
      additional biospecimen collection, including milk samples at 2 and 6-months, maternal body&#xD;
      composition changes using DXA, infant DXA, metabolomic comparison of serial milk samples, and&#xD;
      follow-up to 12 rather than 6-months.&#xD;
&#xD;
      Data Collection Elements:&#xD;
&#xD;
      Maternal Adiposity. Maternal pre-pregnancy BMI status (NW, OW, OB) is the primary exposure&#xD;
      used to power the study. Pre-pregnancy BMI will be determined using first (baseline) clinic&#xD;
      weights from the electronic medical records (EMR) (no more than 90 d. after last menstrual&#xD;
      period), and stature measured by research staff at the mother's first visit to our research&#xD;
      centers. BMI will be categorized as underweight (BMI &lt;18.5), normal weight (BMI 18.5 - &lt;25),&#xD;
      overweight (BMI 25 - &lt;30) and obese (BMI ≥30 kg/m2).&#xD;
&#xD;
      Gestational weight gain (GWG) and postpartum weight loss/retention:Total GWG will be&#xD;
      calculated as the difference between delivery weight and baseline weight (as documented&#xD;
      above). If weight at delivery is not available, the last prenatal weight in the EMR, ≤14 days&#xD;
      from birth, will be used. Trimester specific GWG will be calculated from the EMR. GWG will be&#xD;
      used as a continuous and as a categorical exposure (excessive, appropriate, and insufficient,&#xD;
      according to the IOM 2009 guidelines. Early PP weight loss (from delivery to 1-month&#xD;
      postpartum), and later PP weight loss from 1-month to 3-months PP will be calculated.&#xD;
      Concurrent changes in maternal weight and milk adipocytokine levels from 0 - 1 month and 1 -&#xD;
      3 months will be examined, hypothesizing that greater PP weight loss (lower weight retention)&#xD;
      is associated with lower levels of milk adipocytokines.&#xD;
&#xD;
      Milk Collection: Changes in milk composition will be assessed from 1 to 3 months. Definition&#xD;
      of exclusive breast feeding: Study staff will confirm that all infants have been exclusively&#xD;
      breast milk fed (i.e. no formula, no liquid other than water and no solids) at least 14 days&#xD;
      prior to the 1-month visit and plan to continue exclusively breastfeed to 3 months. Exclusive&#xD;
      breast milk feeding will include any combination of expressed breast milk and breast milk fed&#xD;
      via the breast.&#xD;
&#xD;
      Breast Milk Collection Protocol: Mother and child will report to the study site at 1 and&#xD;
      3-months (± 5 days) postpartum, between 8:00-10:00 am, at least 1½ hours since the last&#xD;
      feeding and while the mother has fasted at least 1 hour. A pre-feeding infant weight will be&#xD;
      obtained using a high sensitivity scale, the mother will be encouraged to feed the child ad&#xD;
      libitum from both breasts until volitionally satisfied, and a postfeeding infant weight will&#xD;
      be obtained (difference = milk output). Questionnaire information, maternal anthropometry,&#xD;
      and infant body composition data will be collected, and 2 hours later, the mother will&#xD;
      provide a single breast expression sample using an electric breast pump (Medela, Inc.,&#xD;
      provided by the study team). Breast milk will be mixed, aliquoted and stored at -80°C.&#xD;
&#xD;
      Milk Adipocytokine Assays: Milk samples will be thawed in the refrigerator and vortexed. Milk&#xD;
      fat will be separated from the aqueous phase by centrifugation at 3,000g for 10 minutes at&#xD;
      4°C. The resulting skimmed milk will be assayed using commercially available immunoassay kits&#xD;
      for insulin, IGF-1/BP, high molecular weight adiponectin, visfatin, leptin, IL-1β, IL-6,&#xD;
      IL-10, and TNF-α. Glucose will be measured by the glucose oxidase method. To examine&#xD;
      additional cytokine and growth factor concentrations (e.g., interleukins, interferons, TGF-&#xD;
      β) in a manner that conserves sample, a multiplex assay (EMD Millipore, Billerica, MA) and&#xD;
      the Luminex 200 Multiplex analyzer will be employed.&#xD;
&#xD;
      Data Analysis for Specific Aim 1: For each of the milk adipocytokines (continuous dependent&#xD;
      variables), separate mixed effects regression models (to account for serial milk data) will&#xD;
      be constructed, first testing crude associations of milk IL-6 at both 1 and 3-months with&#xD;
      each maternal adiposity variable (excessive GWG, pre-pregnancy BMI status, total GWG,&#xD;
      trimester-specific GWG, early and later PP weight loss), and then minimally adjusted models&#xD;
      (also adjusting for infant sex and gestational age, study center (OK or MN), maternal age,&#xD;
      parity, ethnicity, and maternal socioeconomic status) and finally fully-adjusted regression&#xD;
      models including those variables determined to be potential confounders. In secondary&#xD;
      analyses, possible effect modification of the maternal adiposity associations will be&#xD;
      assessed by adding interaction terms. If the interaction term is significant, a stratified&#xD;
      analyses will be conducted.&#xD;
&#xD;
      Data Collection for Specific Aim 2 Infant Body Composition. Total body composition will be&#xD;
      measured using air displacement plethysmography (ADP) i.e. Pea Pod (v 3.1.1), a rapid, valid,&#xD;
      highly reliable (% fat CV%&lt; 2.5% in our hands) method of total body volume estimation from&#xD;
      which total body fat (FM) and fat-free mass (FFM) is determined using prediction equations.&#xD;
      Both the University of Minnesota and the University of Oklahoma have the same ADP (same&#xD;
      manufacturer, model and software versions).&#xD;
&#xD;
      Infant insulin secretion and resistance at 6 months: C-peptide, or connecting peptide, as a&#xD;
      marker of insulin secretion will be collected. Serum C-peptide is secreted in equimolar&#xD;
      amounts by the pancreas as insulin, but is a more stable measure because it is not prone to&#xD;
      degradation following hemolysis. C-peptide was used as a marker of fetal beta cell function&#xD;
      in the HAPO (Hyperglycemia and Adverse Pregnancy Out-come) study to assess the effects of&#xD;
      maternal obesity and gestational diabetes on adverse pregnancy and infant outcomes. Insulin&#xD;
      resistance will be estimated using homeostasis model assessment (HOMA-IR). Blood will be&#xD;
      obtained via heel-stick in the infant at the time of the 6 month visit to the study center,&#xD;
      as is routine in our laboratories, which yields ~ 1.0 cc of blood. Whole blood will be kept&#xD;
      on ice until centrifugation in our laboratories, and 0.5 mL of serum aliquoted at stored at&#xD;
      -80 C until shipped to Dr. Fields' laboratory for analysis using ELISA (Millipore, Billerica,&#xD;
      MA; Intra-assay CV = 5%; Inter-assay CV = 6%). Interpretation of C-peptide requires blood&#xD;
      glucose level which will be measured in the same blood sample using the glucose oxidase&#xD;
      method.&#xD;
&#xD;
      Milk Macronutrient Content: Total fat content will be measured by the Mojonnier method Fatty&#xD;
      acid composition will be assessed by gas chromatography using the International Dairy&#xD;
      Federation (IDF) methods. Other standard methods will quantitate total nitrogen, ash,&#xD;
      moisture, and carbohydrates.&#xD;
&#xD;
      Infant Appetite, Satiety, and Diet: Shortened versions of the infant diet questionnaires used&#xD;
      in the Infant Feeding Practices Study II at 1 month, 3-months, and 6-months will assess&#xD;
      maternal report of infant dietary intake. Maternal perception of infant appetite will be&#xD;
      measured using the Baby Eating Behavior Questionnaire. Infant Sleep: The Sadeh Brief Infant&#xD;
      Sleep Questionnaire has been validated against actigraphy and will be used to assess sleeping&#xD;
      behavior at each visit. Additional Potential Confounders: See Specific Aim 1.&#xD;
&#xD;
      Data Analysis(Specific Aim 2) Statistical Analysis: The over-arching primary hypothesis is&#xD;
      that milk adipocytokine concentrations will be associated with altered body composition from&#xD;
      ages 1 to 6-months, and with elevated C-peptide or HOMA-IR at 6 months, independent of&#xD;
      potential confounders. Example Hypothesis 2.a1: Higher levels of the appetite suppressing&#xD;
      hormone leptin at 1 and/or 3-months will be associated with lower infant weight gain,&#xD;
      reflecting specifically lower FFM gain from 1 - 6 months. We will use mixed effects linear&#xD;
      and logistic regression as the primary analysis approach to address this and related&#xD;
      hypotheses. Growth and body composition data will be serial (0 [for weight], 1, 3, and&#xD;
      6-months), which will be examined using mixed effects models which models the covariance&#xD;
      structure of the repeated measures within subject and allows for subject-specific intercept&#xD;
      and slopes to be modeled. Milk adipocytokines are the independent variables of interest.&#xD;
      Because their individual relationships to infant growth and other outcomes may not be linear,&#xD;
      quintiles or quartiles of milk adipocytokines as well as continuously distributed variables&#xD;
      will be examined. Multiple milk adipocytokines will be included simultaneously in final&#xD;
      models, to test their independent effects on infant outcomes and to assess their aggregate&#xD;
      effects (variance explained).&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Active, not recruiting</overall_status>
  <start_date type="Actual">July 1, 2014</start_date>
  <completion_date type="Anticipated">October 1, 2025</completion_date>
  <primary_completion_date type="Anticipated">March 1, 2025</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Cohort</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>Milk Composition Changes</measure>
    <time_frame>1-3 months post-partum</time_frame>
    <description>Breastmilk hormone concentration changes</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Infant Body Composition Changes</measure>
    <time_frame>0-6 months of age</time_frame>
    <description>Percent Fat Changes</description>
  </secondary_outcome>
  <enrollment type="Anticipated">720</enrollment>
  <condition>Obesity</condition>
  <condition>Pregnancy</condition>
  <condition>Breastmilk Collection</condition>
  <condition>Infant Overnutrition</condition>
  <biospec_retention>Samples Without DNA</biospec_retention>
  <biospec_descr>
    <textblock>
      2 ml aliquots of breastmilk are stored for future chemical analysis.&#xD;
    </textblock>
  </biospec_descr>
  <eligibility>
    <study_pop>
      <textblock>
        (Minneapolis site): In the Twin Cities metro area, subjects will be recruited from patients&#xD;
        who attend medical group clinics for Ob/Gyn care in their second trimester of pregnancy&#xD;
        through the HealthPartners (HP) Institute for Education and Research (HPIER). The HPIER&#xD;
        Data Collection center will recruit eligible subjects via letter and follow-up phone call&#xD;
        for final screening.&#xD;
&#xD;
        (Oklahoma City site): Recruitment in the OKC metro area will be through OUHSC Ob/Gyn&#xD;
        clinic, and local private practice OB/GYN clinics during the second trimester, through the&#xD;
        La Leche League, and public announcements.&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Non-Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Pregnant females&#xD;
&#xD;
          -  21 to 45 years of age at the time of delivery&#xD;
&#xD;
          -  Pre-gravid BMI between 18.5 to 40 kg/m2&#xD;
&#xD;
          -  Healthy pregnancy defined as &lt;3 days in hospital following delivery&#xD;
&#xD;
          -  Report during enrollment procedures that they have social support for and intention to&#xD;
             exclusively breastfeed for at least 3-months&#xD;
&#xD;
          -  If parity &gt;1, report that they successfully breast fed a previous pregnancy for at&#xD;
             least 3 months&#xD;
&#xD;
          -  In positive energy balance&#xD;
&#xD;
          -  Singleton gestation&#xD;
&#xD;
          -  Term pregnancy (gestational age &gt;37 but &lt;42 weeks)&#xD;
&#xD;
          -  Infant birth weight &gt;2,500 grams but &lt;4,500 grams.&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Alcohol consumption &gt;1 drink per week during pregnancy/lactation&#xD;
&#xD;
          -  Tobacco consumption during pregnancy/lactation&#xD;
&#xD;
          -  History/current Type I, II or gestational diabetes&#xD;
&#xD;
          -  Inability to speak/understand English&#xD;
&#xD;
          -  Known congenital metabolic, endocrine disease, or congenital illness affecting infant&#xD;
             feeding/growth&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>0 Years</minimum_age>
    <maximum_age>45 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>David Fields, PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>University of Oklahoma</affiliation>
  </overall_official>
  <overall_official>
    <last_name>Ellen Demerath, PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>University of Minnesota</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>University of Minnesota School of Public Health</name>
      <address>
        <city>Minneapolis</city>
        <state>Minnesota</state>
        <zip>55454</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>University of Oklahoma Health Sciences Center</name>
      <address>
        <city>Oklahoma City</city>
        <state>Oklahoma</state>
        <zip>73104</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>United States</country>
  </location_countries>
  <link>
    <url>https://cnbd.umn.edu/research/milk-study</url>
    <description>The MILk Study website provides information on the study for study participants</description>
  </link>
  <verification_date>April 2023</verification_date>
  <study_first_submitted>September 13, 2017</study_first_submitted>
  <study_first_submitted_qc>October 3, 2017</study_first_submitted_qc>
  <study_first_posted type="Actual">October 4, 2017</study_first_posted>
  <last_update_submitted>April 6, 2023</last_update_submitted>
  <last_update_submitted_qc>April 6, 2023</last_update_submitted_qc>
  <last_update_posted type="Actual">April 7, 2023</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Obesity, Maternal</mesh_term>
    <mesh_term>Obesity</mesh_term>
    <mesh_term>Overnutrition</mesh_term>
    <mesh_term>Infant Nutrition Disorders</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03301753
org study id: 140M50203
secondary id: R01HD080444
nct id: NCT03301753
lead sponsor: 
collaborator: 
collaborator: 
collaborator: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
Today the majority of pregnant women in the United States are either overweight or obese at
      conception with their offspring having greater adiposity at birth, a 2-fold greater risk of
      later obesity, and neonatal insulin resistance. It was long thought that breast milk
      composition was fairly uniform among women, having been optimized through evolutionary time
      to provide adequate sole nutrition for the growing infant regardless of the environmental
      circumstances. However, recent evidence shows that breast milk is a highly complex fluid with
      significant inter-individual variation in hormonal and cytokine concentrations. Pervasive
      maternal obesity is an evolutionarily novel condition for the human species but little effort
      has yet been made to systematically examine how this novel condition is associated with
      breast milk adipose-tissue derived hormone and cytokine (adipocytokine) variation, or whether
      that variation relates to infant metabolic status. The objective of this study is to
      comprehensively assess the "lactational programming" hypothesis, that is, whether or not
      recently documented variation in breast-milk composition is related to both maternal
      adiposity and to infant metabolic status. The central hypothesis is that a graded,
      dose-response relationship between maternal adiposity and adipocytokine concentrations in
      breast milk exists and that milk adipocytokine concentrations are associated with altered
      body composition in their exclusively breast-fed offspring. The results of the study will be
      used to design interventions to reduce maternal weight during pregnancy and lactation and to
      augment lactation education materials to focus on the needs of obese breast-feeding women.
General Study Design A prospective observational pregnancy cohort of 360 non-diabetic
      mothers, who exclusively breastfeed their infants to at least 1 month post-partum, will be
      recruited in the second trimester of pregnancy, across a wide range of maternal pre-pregnancy
      BMI, with equal numbers of normal weight, overweight, and obese women. The women will be
      recruited at two study centers (University of Oklahoma Health Sciences Center in Oklahoma
      City, OK and Health Partners Research Foundation in Saint Paul/Minneapolis, MN), with
      maternal and infant diet, body composition and metabolic health followed prospectively at 1,
      3 and 6-months post-partum in Specific Aims 1 and 2. In Specific Aim 3, a subset of 60 of
      these mother/infant dyads "Mothers in Focus" (30 OB and 30 NW mothers) will be recruited for
      additional biospecimen collection, including milk samples at 2 and 6-months, maternal body
      composition changes using DXA, infant DXA, metabolomic comparison of serial milk samples, and
      follow-up to 12 rather than 6-months.

      Data Collection Elements:

      Maternal Adiposity. Maternal pre-pregnancy BMI status (NW, OW, OB) is the primary exposure
      used to power the study. Pre-pregnancy BMI will be determined using first (baseline) clinic
      weights from the electronic medical records (EMR) (no more than 90 d. after last menstrual
      period), and stature measured by research staff at the mother's first visit to our research
      centers. BMI will be categorized as underweight (BMI <18.5), normal weight (BMI 18.5 - <25),
      overweight (BMI 25 - <30) and obese (BMI ≥30 kg/m2).

      Gestational weight gain (GWG) and postpartum weight loss/retention:Total GWG will be
      calculated as the difference between delivery weight and baseline weight (as documented
      above). If weight at delivery is not available, the last prenatal weight in the EMR, ≤14 days
      from birth, will be used. Trimester specific GWG will be calculated from the EMR. GWG will be
      used as a continuous and as a categorical exposure (excessive, appropriate, and insufficient,
      according to the IOM 2009 guidelines. Early PP weight loss (from delivery to 1-month
      postpartum), and later PP weight loss from 1-month to 3-months PP will be calculated.
      Concurrent changes in maternal weight and milk adipocytokine levels from 0 - 1 month and 1 -
      3 months will be examined, hypothesizing that greater PP weight loss (lower weight retention)
      is associated with lower levels of milk adipocytokines.

      Milk Collection: Changes in milk composition will be assessed from 1 to 3 months. Definition
      of exclusive breast feeding: Study staff will confirm that all infants have been exclusively
      breast milk fed (i.e. no formula, no liquid other than water and no solids) at least 14 days
      prior to the 1-month visit and plan to continue exclusively breastfeed to 3 months. Exclusive
      breast milk feeding will include any combination of expressed breast milk and breast milk fed
      via the breast.

      Breast Milk Collection Protocol: Mother and child will report to the study site at 1 and
      3-months (± 5 days) postpartum, between 8:00-10:00 am, at least 1½ hours since the last
      feeding and while the mother has fasted at least 1 hour. A pre-feeding infant weight will be
      obtained using a high sensitivity scale, the mother will be encouraged to feed the child ad
      libitum from both breasts until volitionally satisfied, and a postfeeding infant weight will
      be obtained (difference = milk output). Questionnaire information, maternal anthropometry,
      and infant body composition data will be collected, and 2 hours later, the mother will
      provide a single breast expression sample using an electric breast pump (Medela, Inc.,
      provided by the study team). Breast milk will be mixed, aliquoted and stored at -80°C.

      Milk Adipocytokine Assays: Milk samples will be thawed in the refrigerator and vortexed. Milk
      fat will be separated from the aqueous phase by centrifugation at 3,000g for 10 minutes at
      4°C. The resulting skimmed milk will be assayed using commercially available immunoassay kits
      for insulin, IGF-1/BP, high molecular weight adiponectin, visfatin, leptin, IL-1β, IL-6,
      IL-10, and TNF-α. Glucose will be measured by the glucose oxidase method. To examine
      additional cytokine and growth factor concentrations (e.g., interleukins, interferons, TGF-
      β) in a manner that conserves sample, a multiplex assay (EMD Millipore, Billerica, MA) and
      the Luminex 200 Multiplex analyzer will be employed.

      Data Analysis for Specific Aim 1: For each of the milk adipocytokines (continuous dependent
      variables), separate mixed effects regression models (to account for serial milk data) will
      be constructed, first testing crude associations of milk IL-6 at both 1 and 3-months with
      each maternal adiposity variable (excessive GWG, pre-pregnancy BMI status, total GWG,
      trimester-specific GWG, early and later PP weight loss), and then minimally adjusted models
      (also adjusting for infant sex and gestational age, study center (OK or MN), maternal age,
      parity, ethnicity, and maternal socioeconomic status) and finally fully-adjusted regression
      models including those variables determined to be potential confounders. In secondary
      analyses, possible effect modification of the maternal adiposity associations will be
      assessed by adding interaction terms. If the interaction term is significant, a stratified
      analyses will be conducted.

      Data Collection for Specific Aim 2 Infant Body Composition. Total body composition will be
      measured using air displacement plethysmography (ADP) i.e. Pea Pod (v 3.1.1), a rapid, valid,
      highly reliable (% fat CV%< 2.5% in our hands) method of total body volume estimation from
      which total body fat (FM) and fat-free mass (FFM) is determined using prediction equations.
      Both the University of Minnesota and the University of Oklahoma have the same ADP (same
      manufacturer, model and software versions).

      Infant insulin secretion and resistance at 6 months: C-peptide, or connecting peptide, as a
      marker of insulin secretion will be collected. Serum C-peptide is secreted in equimolar
      amounts by the pancreas as insulin, but is a more stable measure because it is not prone to
      degradation following hemolysis. C-peptide was used as a marker of fetal beta cell function
      in the HAPO (Hyperglycemia and Adverse Pregnancy Out-come) study to assess the effects of
      maternal obesity and gestational diabetes on adverse pregnancy and infant outcomes. Insulin
      resistance will be estimated using homeostasis model assessment (HOMA-IR). Blood will be
      obtained via heel-stick in the infant at the time of the 6 month visit to the study center,
      as is routine in our laboratories, which yields ~ 1.0 cc of blood. Whole blood will be kept
      on ice until centrifugation in our laboratories, and 0.5 mL of serum aliquoted at stored at
      -80 C until shipped to Dr. Fields' laboratory for analysis using ELISA (Millipore, Billerica,
      MA; Intra-assay CV = 5%; Inter-assay CV = 6%). Interpretation of C-peptide requires blood
      glucose level which will be measured in the same blood sample using the glucose oxidase
      method.

      Milk Macronutrient Content: Total fat content will be measured by the Mojonnier method Fatty
      acid composition will be assessed by gas chromatography using the International Dairy
      Federation (IDF) methods. Other standard methods will quantitate total nitrogen, ash,
      moisture, and carbohydrates.

      Infant Appetite, Satiety, and Diet: Shortened versions of the infant diet questionnaires used
      in the Infant Feeding Practices Study II at 1 month, 3-months, and 6-months will assess
      maternal report of infant dietary intake. Maternal perception of infant appetite will be
      measured using the Baby Eating Behavior Questionnaire. Infant Sleep: The Sadeh Brief Infant
      Sleep Questionnaire has been validated against actigraphy and will be used to assess sleeping
      behavior at each visit. Additional Potential Confounders: See Specific Aim 1.

      Data Analysis(Specific Aim 2) Statistical Analysis: The over-arching primary hypothesis is
      that milk adipocytokine concentrations will be associated with altered body composition from
      ages 1 to 6-months, and with elevated C-peptide or HOMA-IR at 6 months, independent of
      potential confounders. Example Hypothesis 2.a1: Higher levels of the appetite suppressing
      hormone leptin at 1 and/or 3-months will be associated with lower infant weight gain,
      reflecting specifically lower FFM gain from 1 - 6 months. We will use mixed effects linear
      and logistic regression as the primary analysis approach to address this and related
      hypotheses. Growth and body composition data will be serial (0 [for weight], 1, 3, and
      6-months), which will be examined using mixed effects models which models the covariance
      structure of the repeated measures within subject and allows for subject-specific intercept
      and slopes to be modeled. Milk adipocytokines are the independent variables of interest.
      Because their individual relationships to infant growth and other outcomes may not be linear,
      quintiles or quartiles of milk adipocytokines as well as continuously distributed variables
      will be examined. Multiple milk adipocytokines will be included simultaneously in final
      models, to test their independent effects on infant outcomes and to assess their aggregate
      effects (variance explained).
observational model: Cohort
time perspective: Prospective
measure: Milk Composition Changes
time frame: 1-3 months post-partum
description: Breastmilk hormone concentration changes
measure: Infant Body Composition Changes
time frame: 0-6 months of age
description: Percent Fat Changes
2 ml aliquots of breastmilk are stored for future chemical analysis.
study pop: 
sampling method: Non-Probability Sample
criteria: 
gender: All
minimum age: 0 Years
maximum age: 45 Years
healthy volunteers: Accepts Healthy Volunteers
last name: David Fields, PhD
role: Principal Investigator
affiliation: University of Oklahoma
last name: Ellen Demerath, PhD
role: Principal Investigator
affiliation: University of Minnesota
facility: 
facility: 
country: United States
url: https://cnbd.umn.edu/research/milk-study
description: The MILk Study website provides information on the study for study participants
responsible party type: Sponsor
mesh term: Obesity, Maternal
mesh term: Obesity
mesh term: Overnutrition
mesh term: Infant Nutrition Disorders
sharing ipd: No