Leptin, insulin and TNF-alpha in weight loss.

Forty-eight morbidly obese patients were placed on a very low calorie (800 kcal) formula diet (OPTIFAST) for a 10-week period with the goal of achieving 10% weight loss within this time. Weekly serum leptin measurements were performed to determine whether changes in this adipose protein would serve as a useful marker of acute and chronic weight loss compliance. In the basal state, serum leptin averaged 56.9 +/- 5.8 ng/ml (SE) in the 24 successful (S) patients, and 67.7 +/- 6.7 ng/ml in the non-successful (N-S) group. During the first week of weight loss there was little change in leptin despite an average weight loss of 2.2%, but after 4 weeks serum leptin decreased by 36% in the S group, and 20% in the N-S group. After 10 weeks, the S group averaged 13.6% weight loss and the serum leptin decreased to 50% of starting levels. In the 24 N-S patients, the mean weight loss was 7.0%, and serum leptin decreased by 22%, remaining unchanged in the final 6 weeks despite a weight loss of 3.6% in this time. On a week-to-week basis serum leptin changed concordantly with weight loss only two-thirds of the time. In a subgroup of 14 patients (8 S+6 N-S), serial assessments of serum leptin, insulin and tumor necrosis factor-alpha (TNF-alpha) were performed. Serum insulin levels decreased with weight loss similar in magnitude to that noted for leptin; however, the insulin changes occurred more rapidly. Serum TNF-alpha also decreased with weight loss, but the weekly changes were more erratic, with a concordance rate of only 48%. In summary, serum leptin, insulin and TNF-alpha all decreased during a rapid weight loss program but at differing rates and variability, precluding their usefulness as markers of week-to-week weight loss compliance.

Incipient and overt diabetic nephropathy in African Americans with NIDDM.

OBJECTIVE--To determine the prevalence of incipient and overt nephropathy in African-American subjects with non-insulin-dependent diabetes mellitus (NIDDM) attending a hospital clinic. Contributory factors, such as blood pressure (BP), duration and age at onset of diabetes, hyperglycemia, hyperlipidemia, and body mass index (BMI) also were evaluated. RESEARCH DESIGN AND METHODS--We recruited 116 African-American subjects with NIDDM for this cross-sectional, descriptive, and analytical study. BP, BMI, 24-h urine albumin excretion, creatinine clearance, serum creatinine, lipids, and GHb levels were measured. Albumin excretion rate (AER) was calculated, and subjects were divided into three groups: no nephropathy (AER < 20 micrograms/min), incipient nephropathy (AER 20-200 micrograms/min), and overt nephropathy (AER > 200 micrograms/min). Frequency of hypertension and nephropathy was analyzed by chi 2 testing, group means were compared using analysis of variance, and linear correlations were performed between AER and other variables. Multiple regression analysis was used to examine the association of these variables while controlling for the effects of other variables. RESULTS--Increased AER was present in 50% of our subjects; 31% had incipient and 19% had overt nephropathy. Hypertension was present in 72.4%; nephropathy, particularly overt nephropathy, was significantly more prevalent in the hypertensive group. Mean BP and diastolic blood pressure (dBP) were higher in the groups with incipient and overt nephropathy, and systolic blood pressure (sBP) was increased in overt nephropathy. Men with either form of nephropathy had higher sBP, dBP, and mean BP, whereas only women with overt nephropathy had increased sBP and mean BP. Subjects with incipient or overt nephropathy had a longer duration of diabetes, and those with overt nephropathy had a younger age at onset of diabetes. By multiple regression analysis, AER correlated with younger age at diabetes onset, but not with diabetes duration. No correlation with age, lipid levels, or GHb was noted. BMI correlated with AER. CONCLUSIONS--Incipient and overt nephropathy were observed frequently in these African-American subjects with NIDDM. Albuminuria correlated with BP, younger age at diabetes onset, and BMI. Association of albuminuria and increased cardiovascular mortality may place 50% of inner-city African-American patients with NIDDM at risk for developing cardiovascular complications.