Natasha J. Lawrence

The prevalence of polycystic ovaries in women with a history of gestational diabetes

Women with a history of gestational diabetes mellitus (GDM) and women with polycystic ovary syndrome (PCOS) both demonstrate abnormalities in insulin action and secretion, and both are at increased risk of developing type 2 diabetes. To determine whether these similarities reflect a common pathophysiological basis, we examined the prevalence of ultrasound‐based polycystic ovarian morphology in a large multiethnic group of women with a history of GDM and a group of women who had normal glucose tolerance during pregnancy.

Insulin resistance and beta-cell dysfunction in normoglycaemic European women with a history of gestational diabetes.

objective Women with previous gestational diabetes (GDM) are at increased risk of subsequent type 2 diabetes. To characterize early metabolic abnormalities associated with this increased risk, we studied normoglycaemic women with a history of GDM.

The impact of ethnicity on glucose regulation and the metabolic syndrome following gestational diabetes.

Aims/hypothesisWe assessed the impact of ethnic origin on metabolism in women following gestational diabetes mellitus (GDM).Materials and methodsGlucose regulation and other features of the metabolic syndrome were studied at 20.0 (18.2–22.1) months (geometric mean [95% CI]) post-partum in women with previous GDM (185 European, 103 Asian-Indian, 80 African-Caribbean). They were compared with the same features in 482 normal control subjects who had normal glucose regulation during and following pregnancy.ResultsImpaired glucose regulation or diabetes by WHO criteria were present in 37% of women with previous GDM (diabetes in 17%), especially in those of African-Caribbean and Asian-Indian origin (50 and 44%, respectively vs 28% in European, p=0.009). BMI, waist circumference, diastolic blood pressure, fasting triglyceride and insulin levels, and insulin resistance by homeostatic model assessment (HOMA), were increased following GDM (p<0.001 for all, vs control subjects). Where glucose regulation was normal following GDM, basal insulin secretion (by HOMA) was high (p<0.001 vs control subjects). Irrespective of glucose regulation in pregnancy, Asian-Indian origin was associated with high triglyceride and low HDL cholesterol levels, and African-Caribbean with increased waist circumference, blood pressure, and insulin levels, together with insulin resistance and low triglyceride concentrations. Nonetheless, the GDM-associated features were consistent within each ethnic group. The metabolic syndrome by International Diabetes Federation criteria was present in 37% of women with previous GDM, especially in non-Europeans (Asian-Indian 49%, African-Caribbean 43%, European 28%, p=0.001), and in 10% of controls.Conclusions/interpretationFollowing GDM, abnormal glucose regulation and the metabolic syndrome are common, especially in non-European women, indicating a need for diabetes and cardiovascular disease prevention strategies.

Women with a history of gestational diabetes of European and South Asian origin are shorter than women with normal glucose tolerance in pregnancy

SUMMARY

The circadian rhythm of leptin is preserved in growth hormone deficient hypopituitary adults

Leptin acts as a satiety factor in regulating food intake and body homeostasis, but its regulation is not well defined. Specific leptin receptors have been found in the brain and it has been hypothesized that leptin production by adipose tissue is under neuroendocrine control. A circadian rhythm has been demonstrated with highest leptin levels between midnight and early morning hours. The possibility that hypopituitarism (or pituitary surgery ± radiotherapy) abolishes this leptin rhythm was investigated by measuring serum leptin levels during a 24‐h period in patients with impaired pituitary function.

Relation between insulin kinetics and insulin sensitivity in pregnancy.

Background Different time‐concentration profiles of plasma insulin following insulin modification of a frequently sampled intravenous glucose‐tolerance‐test (FSIVGTT) were observed in a study investigating maternal metabolism and fetal macrosomia. We aimed to investigate whether these differences were related to the volume of distribution of insulin, insulin clearance, or both.

Elevation of soluble E-selectin levels following gestational diabetes is restricted to women with persistent abnormalities of glucose regulation

objective Increased levels of the soluble adhesion molecule sE‐selectin have been reported in normoglycaemic women with previous gestational diabetes but not in other groups at increased risk of future type 2 diabetes. To explore the basis for these discrepant findings, we studied the relationship between sE‐selectin and glucose regulation in a large group of women with previous gestational diabetes.

Effects of growth hormone treatment on very-low-density lipoprotein apolipoprotein B100 turnover in adult hypopituitarism

Adult hypopituitarism is associated with hyperlipidemia, mainly due to an increase of very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) levels. Recent studies have shown that such patients exhibit increased hepatic secretion of VLDL apolipoprotein B100 (VLDL apo B100). To examine the effects of growth hormone (GH) replacement on VLDL apo B100 turnover, 13 GH-deficient hypopituitary patients (8 women and 5 men; aged 47 +/- 3 years, mean +/- SEM; body mass index [BMI], 30 +/- 2 kg/m2) entered a double-blind placebo-controlled study for 6 months (GH 0.125 IU/kg/wk for 4 weeks, and then 0.25 IU/kg/wk). GH was subsequently used in all patients for a further 6 months. A 6-hour [1-13C] leucine infusion was administered at baseline and at 6 months. The secretion rate of VLDL apo B100 was derived by kinetic analysis following quantitation of isotopic enrichment by gas chromatography/mass spectrometry. The GH-treated group (6 patients) demonstrated a similar fractional secretion rate (FSR) for VLDL apo B100 at 0 and 6 months. The pool size and absolute secretion rate (ASR) also were unaffected significantly by GH therapy. No significant changes were observed in the placebo group (7 patients). Treatment with GH for 6 months caused an increase in the high-density lipoprotein (HDL) cholesterol concentration (13 patients, 1.27 +/- 0.13 v 1.16 +/- 0.10 mmol/L, respectively, P = .05), whereas total cholesterol and triglyceride concentrations did not change. Nonesterified fatty acids (NEFAs) increased during GH therapy (471 +/- 43 micromol/L at 6 months v 349 +/- 49 micromol/L at baseline, P < .0005). The data suggest that GH does not affect VLDL apo B100 turnover in a significant way.