Clinical, endocrine and metabolic studies in the kindred of familial partial lipodystrophy--a syndrome of insulin resistance.

OBJECTIVE: To study clinical, endocrine and metabolic profiles in the kindred of subjects with familial partial lipodystrophy (FPLD, Dunnigan type). MATERIAL AND METHODS: Twenty two relatives (10 males, 12 females), from an extended family with FPLD, were assessed for the phenotypic features, impaired glucose tolerance (IGT)/diabetes mellitus (DM), dyslipidemia and the presence of insulin resistance. Plasma glucose and serum lipids were measured using glucose oxidase and standard colorimetric methods. Serum insulin was estimated by radioimmunoassay. RESULTS: The age was 12 to 67 years, two being adolescents. Two of the 20 adults were overweight and eight were underweight; BMI (adults) was 15.5 to 28.5. Features of FPLD were evident among eight out of 12 women. This typical phenotype was not obvious in all 10 male members. Varying degree of Hirsuitism was observed in four of 12 women, acanthosis nigricans in 11 out of 22 members and skin tags were present in only eight of 22; hypertension in six members and diabetes in four. Eleven members had either impaired glucose tolerance (IGT) (n=7), or DM (n=4). Ten of 20 members showed hyperinsulinemic response on oral glucose tolerance test (OGTT). Dyslipidemia was present in 13 family members. CONCLUSION: The majority (2/3rd) of female members showed typical phenotypic features of FPLD, with a clustering of cardiovascular risk factors and insulin resistance syndrome. More than half the men without phenotypic features of FPLD had either IGT/DM, dyslipidemia, hypertension or cardiovascular disease.

Serum leptin concentrations in hyperinsulinemia in the sets of obese, lipodystrophic and/or non-obese patients.

OBJECTIVE: To study the relationship between serum leptin and circulating insulin under basal and in response to oral glucose administration in hyperinsulinemic patients with or without obesity. MATERIAL AND METHOD: Fifteen female patients of known hyperinsulinemia provided material for the study. Leptin and insulin in sera were estimated by radioimmunoassay methods. RESULTS: Eight of the 15 hyperinsulinemic patients with high body mass index (BMI) (31 +/- 0.94 kg/m2) had significantly (p < 0.01) elevated serum leptin concentrations (26.1 +/- 2 ng/ml) as compared to the levels in the remaining seven non-obese hyperinsulinemic patients with BMI of 20 +/- 1.0 kg/m2; their mean levels of serum leptin were low 5.7 +/- 1.1 ng/ml. Four of the latter group had face-sparing partial lipodystrophy. The mean circulating leptin concentrations in the control group of seven healthy normoinsulinemic and regularly menstruating women with normal BMI (19 +/- 0.95 kg/m2) were 13.7 +/- 1.8 ng/ml. DISCUSSION: The results of the present study in 15 hyperinsulinemic patients show that circulating levels of leptin are not related to serum insulin. However, there was a positive correlation with BMI. An interesting observation of the study is that, notwithstanding the normal BMI, the group of hyperinsulinemic patients with face-sparing partial lipodystrophy had the lowest levels of circulating leptin concentrations. They were closer to the values found in prepubertal girls.

Prevalence of islet cell antibodies and its correlation with glucose and insulin response to oral glucose tolerance test in 1st degree relatives of insulin dependent diabetes mellitus probands.

93 first degree relatives (1st DR) of insulin dependent diabetes mellitus (IDDM) patients were investigated for detection of islet cell antibodies (ICA) and beta cell functional status. ICA were detected in 26.9% Ist DR subjects (25/93), equally in parents, siblings and offspring. Normal (n = 16), impaired (n = 5) and diabetic (n = 4), glucose curves were seen in 1st DR. Low insulin levels were observed in parents and siblings with normal glucose tolerance test (N-GTT) at 90 min (p < 0.05), and (p < 0.0005) relatives with impaired glucose tolerance and diabetes. Insulin release to glucose (IRG-insulinogenic index) in control group was 352 +/- 42 mu U/mg. From the group of 25 ICA positive cases, 4 had mean IRG of 394 +/- 70 mu U/mg (group A) comparable to control, and had N-GTT; 12 had mean IRG of 107 +/- 15.9 mu U/mg (group B) significantly low (P < 0.005) compared to controls and group A and 9 showed IRG of 75 +/- 29.3 mu U/mg, lower than group B (NS) with abnormal response to glucose load. Loss of insulin secretory ability thus can precede hyperglycemia by years. The ICA positive relatives were grouped based on the immunological status with their probands. ICA status in probands does not give an idea about ICA status in their relatives. This indepth study leads to understand the correlation of genetic, metabolic and immunological parameters for early detection of IDDM in first degree relatives.

Prevalence of islet cell antibodies and B cell functional status in insulin dependent diabetes.

As autoimmunity is an important factor in the etiopathogenesis of IDDM, 85 ketosis prone i.e. insulin dependent diabetes (IDD) were evaluated for immunological and beta cell functional status. Islet cell antibodies (ICA) against purified islet cells used in Microwell ELISA Method, were detected in 27.1% of cases (23/85). There was a prevalence of 36.4% of ICA positivity in newly diagnosed cases and its prevalence declined with duration. The highest ICA positivity was observed in fourth decade of life. 17 of the 23 ICA positive cases (73.9%) had a mean duration of 2.1 years whereas the remaining 6/23 (26.1%) had a mean duration of 9 years. Females showed a younger age of onset of diabetes. Only one female with duration of 10 years tested positive for ICA.ICA positive males had later age of onset and longer duration of diabetes as compared to ICA positive females. Ten ICA positive cases studied were showing non-significant C-peptide (CP) release (after glucose load) in comparison to negative cases (14); p < 0.05, 8 of these cases were with < 3 months duration. Significantly low delta % C-peptide response implies a low residual beta-cell function and further loss of beta cell function earlier in ICA +ve cases. Thus this study leads to understand in depth the immune mechanism of IDDM.