***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Chronic kidney disease ( CKD ) is an increasing cause of morbidity and mortality in the United States . Prospect i ve data on risk factors for CKD are limited to men , and few studies examine the importance of smoking . The authors performed a community-based , prospect i ve observational study of 20-yr duration to examine the association between hypertension and  smoking  on the future risk of CKD in 23,534 men and women in Washington County , Maryl and . CKD was identified as end-stage renal disease in the Health Care Financing Administration data base or kidney disease listed on the death certificate . All cases were confirmed as CKD by medical chart review . Adjusted relative hazards of CKD were modeled using Cox proportional hazards regression including age as the time variable and baseline BP , cigarette smoking , gender , and diabetes status as risk factors . The adjusted hazard ratio ( 95 % confidence interval ) of developing CKD among women was 2.5 ( 0.05 to 12.0 ) for normal BP , 3.0 ( 0.6 to 14.4 ) for high-normal BP , 3.8 ( 0.8 to 17.2 ) for stage 1 hypertension , 6.3 ( 1.3 to 29.0 ) for stage 2 hypertension , and 8.8 ( 1.8 to 43.0 ) for stages 3 or 4 hypertension compared with individuals with optimal BP . In men , the relationship was similar but somewhat weaker than in women , with corresponding hazard ratios of 1.4 ( 0.2 to 12.1 ) , 3.3 ( 0.4 to 25.6 ) , 3.0 ( 0.4 to 22.2 ) , 5.7 ( 0.8 to 43.0 ) , and 9.7 ( 1.2 to 75.6 ) , respectively . Current cigarette smoking was also significantly associated with risk of CKD in both men and women ( hazard ratio in women 2.9 [ 1.7 to 5.0 ] and in men 2.4 [ 1.5 to 4.0 ] ) . A large proportion of the attributable risk of CKD in this population was associated with stage 1 hypertension ( 23 % ) and cigarette smoking ( 31 % ) . In conclusion , CKD risk shows strong grade d relationships to the sixth report of the Joint National Committee ( JNC-VI ) on Prevention , Detection Evaluation and Treatment of High BP criteria for BP , to diabetes , and to current cigarette smoking that are at least as strong in women as in men An increased albumin excretion rate ( AER ) is associated with impaired glucose tolerance and diabetes mellitus in some population s , but data on Americans of Northern European origin are lacking . In 1986 - 1987 , AER and creatinine clearance were measured in 455 adults in a survey of the population of Wadena , Minnesota . Thirty-five subjects ( 8 % ) had an AER > or = 15 micrograms/minute , and eight of these had overt proteinuria ( AER > or = 175 micrograms/minute ) . AER and creatinine clearance were uncorrelated except when AER was increased . Unadjusted mean AER in a stratified r and om sample of adults ( n = 374 ) was 3.6 micrograms/minute . Adjusted values for 277 subjects with normal glucose tolerance and for 80 subjects with impaired glucose tolerance were very similar ( 3.8 and 3.7 micrograms/minute , respectively ) , whereas mean AER was 5.4 micrograms/minute for persons with non-insulin-dependent diabetes mellitus ( NIDDM ) who were not taking insulin and 9.4 micrograms/minute for persons with NIDDM who were taking insulin ( p < 0.0001 ) . After adjustment for age , mean creatinine clearance was unrelated to glucose tolerance . Systolic blood pressure was a major determinant of increased AER ( p < 0.0001 ) and lowered creatinine clearance ( p = 0.0011 ) , independently of diabetes . AER was stable over 5 years among the 321 cases who were not taking insulin and were not severely hypertensive . The decrease in creatinine clearance was greater in ex-smokers and current smokers than in nonsmokers . The authors conclude that hypertension and NIDDM were independently associated with the risk of kidney damage in this population , as indicated by a higher AER . High-normal blood pressure , but not impaired glucose tolerance , was associated with microalbuminuria . These relatively mild changes may reflect an ethnically based resistance to the damaging effects of hyperglycemia on the kidney . Smoking may accelerate the aging-related decline in glomerular filtration rate BACKGROUND Proteinuria is a major risk factor for the progression of kidney disease and the development of cardiovascular disease . Little is known , however , about risk factors for incident proteinuria . METHODS We conducted a 10-year prospect i ve cohort study of 104,523 Korean men and 52,854 women , aged 35 to 59 years , who attended Korea Medical Insurance Corporation health examinations and who did not have proteinuria at baseline .  Incident proteinuria was assessed at biennial examinations during the next 10 years . We performed Cox proportional hazards analyses . RESULTS During 10 years of follow-up , proteinuria developed in 3951 men ( 3.8 % ) and 1527 women ( 2.9 % ) . The adjusted relative risk ( RR ) of proteinuria associated with diabetes was 3.27 ( 95 % confidence interval [ CI ] , 2.98 - 3.58 ) in men and 2.60 ( 95 % CI , 1.98 - 3.43 ) in women ; with body mass index ( calculated as weight in kilograms divided by the square of height in meters ) , it was 1.43 ( 95 % CI , 1.35 - 1.50 ) in men and 1.45 ( 95 % CI , 1.35 - 1.55 ) in women per 5-U increment . Compared with subjects with serum cholesterol levels of less than 200 mg/dL ( < 5.18 mmol/L ) , the adjusted RRs associated with serum cholesterol levels of 200 to 239 mg/dL ( 5.18 - 6.19 mmol/L ) and 240 mg/dL or more ( > or = 6.22 mmol/L ) were 1.13 ( 95 % CI , 1.05 - 1.21 ) and 1.40 ( 95 % CI , 1.27 - 1.54 ) , respectively , in men and 1.14 ( 95 % CI , 1.01 - 1.28 ) and 1.22 ( 95 % CI , 1.00 - 1.37 ) , respectively , in women . Persons with stages 1 and 2 hypertension had a greater adjusted RR of incident proteinuria compared with those with normal blood pressure ( 1.62 [ 95 % CI , 1.47 - 1.79 ] and 2.06 [ 95 % CI , 1.81 - 2.34 ] , respectively , in men and 1.37 [ 95 % CI , 1.14 - 1.65 ] and 2.10 [ 95 % CI , 1.59 - 2.76 ] , respectively , in women ) . CONCLUSIONS Fasting glucose and cholesterol levels , body mass index , and blood pressure were direct and independent predictors of incident proteinuria in Korean adults . These associations were present even at low levels of exposure , emphasizing the importance of early detection and management of these modifiable risk factors For determining whether smoking is associated with an increased risk for chronic renal failure ( CRF )  overall and by type of renal disease , smoking data were analyzed from a nationwide population -based case-control study . Eligible as cases were native 18- to 74-yr-old Swedes whose serum creatinine for the first time and permanently exceeded 3.4 mg/dl ( men ) or 2.8 mg/dl ( women ) . A total of 926 cases ( 78 % of all eligible ) and 998 control subjects ( 75 % of 1330 r and omly selected subjects from the source population ) , frequency matched to the cases by gender and age within 10 yr , were included . A face-to-face interview and a self-administered question naire provided information about  smoking habits  and other lifestyle factors . Logistic regression models estimated odds ratios ( OR ) as measures of relative risk for disease-specific types of CRF among smokers compared with never-smokers . Despite a modest and nonsignificant overall association , the risk increased with high daily doses ( OR among smokers of > 20 cigarettes/d , 1.51 ; 95 % confidence interval [ CI ] , 1.06 to 2.15 ) , long duration ( OR among smokers for > 40 yr , 1.45 ; 95 % CI , 1.00 to 2.09 ) , and a high cumulative dose ( OR among smokers with > 30 pack-years , 1.52 ; 95 % CI , 1.08 to 2.14 ) . Smoking increased risk most strongly for CRF classified as nephrosclerosis ( OR among smokers with > 20 pack-years , 2.2 ; 95 % CI , 1.3 to 3.8 ) , but significant positive associations were also noted with glomerulonephritis . This study thus suggests that heavy cigarette smoking increases the risk of CRF for both men and women , at least CRF classified as nephrosclerosis and glomerulonephritis BACKGROUND The natural history of diabetic nephropathy is well defined in type 1 diabetes , but to a lesser degree in type 2 diabetes , possibly due to diversity of involved risk-factors . The main aim of the study was to assess modifiable and nonmodifiable risk-factors in the development of persistent proteinuria in patients with type 2 diabetes mellitus . METHODS A r and om sample of 90 diabetic patients , regularly checked up at the Department of Endocrinology , was selected and followed up in a period of 5 years . There were 46 males and 44 females , aged 51.8 + /- 9.9 years , with average duration of disease of 6.8 + /- 5.2 years , including 58 ( 64.4 % ) hypertensive patients and 58 ( 64.4 % ) smokers . All the participants had fasting and postpr and ial glycaemia , Hbalc , 24/hour proteinuria and blood pressure measured . Only 4 ( 4.4 % ) persons had 24/h proteinuria > 200 mg/d at the beginning of the study . RESULTS In a 5 year period , 21 ( 23.3 % ) patient developed proteinuria of > 200 mg/d . The main prognostic factors were Hbalc values ( RR 3.5 , p = 0.03 ) , duration of the disease ( RR 3.1 , p = 0.02 ) , hypertension ( RR 2.9 , p = 0.02 ) , with stronger impact of diastolic than systolic values ( RR 2.01 vs RR 1.83 ) , age ( RR 1.35 , p = 0.02 ) , glycaemia with stronger correlation of postpr and ial than fasting values ( RR 1.52 vs 1.34 ) , smoking ( RR 1.26 , p = 0.06 ) while sex and BMI values were not strongly associated with the development of the proteinuria ( RR 1.09 and RR 1.01 respectively ) . CONCLUSIONS Results indicate that , in addition to glycemic control , control of additional modifiable risk-factors , particularly hypertension and smoking , is of utmost importance in the treatment of patients with type 2 diabetes mellitus CONTEXT The explanation for the excess risk for diabetic renal disease in blacks is uncertain . OBJECTIVES To compare the incidence of early renal function decline in black and white adults with diabetes and to examine possible explanatory factors for racial differences . DESIGN Prospect i ve cohort study . SETTING Four US communities participating in the Atherosclerosis Risk in Communities study . PARTICIPANTS Community-based sample of 1434 diabetic adults aged 45 to 64 years . MEASUREMENTS Detailed baseline assessment using structured interview , results of physical examination , and laboratory measurements .  MAIN OUTCOME Development of early renal function decline defined by an increase in serum creatinine of at least 35.4 micromol/L ( 0.4 mg/dL ) during 3 years of follow-up . RESULTS During 3 years of follow-up , early renal function decline developed in 45 blacks ( 28.4 per 1000 person-years [ PY ] ) and 25 whites ( 9.6 per 1000 PY ) . After adjustment for age , sex , and baseline serum creatinine level , early renal function decline was more than 3 times as likely to develop in blacks than whites ( odds ratio , 3.15 ; 95 % confidence interval , 1.86 - 5.33 ) . Additional adjustment for education , household income , health insurance , fasting glucose level , mean systolic blood pressure , smoking history , 
    Output:
    
Conclusions : This comprehensive review reveals overall evidence for current cigarette smoking as a risk factor for incident chronic kidney disease .