A 65-year-old female consulted our office for naturopathic primary-care support for a myriad of conditions, which included diabetes with weight gain, chronic fatigue, depression with emotional lability, frequent colds, and recurrent urinary tract infections. The latter was attributed to a medullary sponge kidney as was her history of kidney stones and hypertension. The patient also suffered with long-standing acid reflux and was prone to irritable bowel with diarrhea. She had also suffered with multiple abscesses in the past as well as poor generalized wound healing. A history of fibroadenomas was also noted. The patient recollected, “never being well”, even as a child. She described her diet as a child as “deficient” and consisted mostly of canned beans and bread, which she attributed to her poor socioeconomic status as a child.
Pharmacological management of her diabetic condition included the use of metformin/sitagliptin (1,000 mg/50 mg, taken twice per day) and gliclazide (30 mg), also taken twice per day.
Additional medications included ramipril (5 mg/day), ranitidine (150 mg, twice per day), low-dose aspirin (81 mg/ day), hydrochlorothiazide (25 mg/day), allopurinol (100 mg/ day), citalopram (40 mg/day), and mirabegron (50 mg/day).
Physical examination revealed a 1.69 m (66.5 inch), 88.5 kg (195.0 lb) female. Body mass index was calculated at 31.0 (Obese Class I) (32). Central waist measurement was 112 cm, while her hips measured 118 cm. Blood pressure was 114/64 mmHg, measured at the left brachial artery. Bioimpedance analysis revealed a lean body mass of 49.9 kg (111.0 lbs) and a fat mass of 38.0 kg (84.0 lbs).
Laboratory assessment prior to date of initial consult (June 2017) revealed a HBA1C of 7.8% and a random glucose of 6.5 mmol/L. Total cholesterol (TC) was 4.68 mmol/L, triglycerides (TG) were 2.63 mmol/L, high-density lipoproteins (HDL) was 1.04 mmol/L, low-density lipoproteins (LDL) was 2.44 mmol/L, and TC:HDL was 4.5. Alanine aminotransferase was 55 U/L, while creatinine was 79 μmol/L.
The formula for computing Cockcroft-Gault is given by CrCl = ((140 - age) * adjusted weight * (gender_coefficient)) / (serum creatinine * 72), where the gender_coefficient is 1 if male, and 0.85 if female. The serum creatinine concentration is in mg/dL.
The patient's gender is female, which means that the gender coefficient is 0.85.
The patient is 65 years old. 
The concentration of creatinine is 79.0 µmol/L. We need to convert the concentration to mg/dL. Let's first convert the mass of creatinine from µmol to mg. The mass of creatinine is 79.0 µmol. To convert 79.0 µmol of creatinine to mol, multiply by the conversion factor 1e-06, giving us 79.0 µmol creatinine * 1e-06 mol/µmol = 7.9e-05 mol creatinine. To convert from mol creatinine to grams, multiply by the molar mass 113.12 g/mol, which will give 7.9e-05 mol creatinine * 113.12 g/mol = 0.009 g creatinine. To convert 0.009 g of creatinine to mg, multiply by the conversion factor 1000.0, giving us 0.009 g creatinine * 1000.0 mg/g = 9.0 mg creatinine. The current volume unit is L and the target volume unit is dL. The conversion factor is 10.0 dL for every unit of L. Our next step will be to divide the mass by the volume conversion factor of 10.0 to get the final concentration in terms of mg/dL. This will result to 9.0 mg creatinine/10.0 dL = 0.9 mg creatinine/dL. The concentration value of 79.0 µmol creatinine/L converts to 0.9 mg creatinine/dL. 
The formula for computing the patient's BMI is (weight)/(height * height), where weight is the patient's weight in kg and height is the patient's height in m.
The patient's height is 1.69 m. The patient's weight is 88.5 kg. The patient's bmi is therefore 88.5 kg / (1.69 m * 1.69 m) = 30.986 kg/m^2.The patient's BMI is 31.0, indicating they are overweight/obese.
Because the patient is overweight/obese, we use the adjusted body weight formula to get the adjusted weight used for Cockroft-Gault Equation. Shown below is the computation for IBW (ideal body weight).
The patient's gender is Female.
The patient's height is 1.69 m, which is 1.69 m * 39.3701 in/m = 66.535 in. 
For females, the ideal body weight (IBW) is calculated as follows:
IBW = 45.5 kg + 2.3 kg * (height (in inches) - 60)
Plugging in the values gives us 45.5 kg + 2.3 kg * (66.535 (in inches) - 60) = 60.53 kg.
Hence, the patient's IBW is 60.53 kg.Shown below is the computation for ABW (adjusted body weight).
To compute the ABW value, apply the following formula: ABW = IBW + 0.4 * (weight (in kg) - IBW (in kg)). ABW = 60.53 kg + 0.4 * (88.5 kg  - 60.53 kg) = 71.718 kg. The patient's adjusted body weight is 71.718 kg.

Using the Cockcroft-Gault equation:
CrCl = ((140 - age) * adjusted weight * gender_coefficient) / (serum creatinine * 72).
Plugging the patient's values gives us ((140 - 65) * 71.718 * 0.85) / (0.9 * 72) = 70.556 mL/min. Hence, the patient's creatinine clearance is 70.556 mL/min.