Various and sundry recent publications

Abstract

An analysis from the nearly 80 000-person Nursesʼ Health Study 1993 to 2017 dataset found approximately 10% of the population studied having had had either irregular menstrual cycles or average cycle length >40 days at age 29 to 46 years. This was associated with ~40% greater premature (before age 70) mortality, with the risk particularly strong for cardiovascular (CV) mortality. The link to the insulin resistance syndrome and subsequent diabetes seems inescapable, with the clinical suggestion that menstrual history remains an important aspect of the medical history. Using estimated glucose disappearance rate as a measure of insulin sensitivity calculated from its negative association with waist circumference, the presence of hypertension, and the glycosylated hemoglobin (HbA1c) level, the authors showed association of insulin resistance with total CV events, coronary artery events, and all-cause mortality in 774 persons with type 1 diabetes over 10-year follow-up. Using data taken from 72 prospective cohort studies with >2.5 million participants, with up to 15 years follow-up, waist circumference was positively and hip circumference negatively associated with all-cause mortality. The subset of studies adjusting for body mass index (BMI) showed even stronger associations, suggesting that clinicians may err in relying on BMI, rather than using these readily obtained measurements in deriving information which may have more direct association with insulin resistance than does body weight. Comparing 11 diabetic persons with carefully supervised diet-induced weight loss vs 11 with similar weight loss following gastric bypass, glucose-lowering meds were reduced by three quarters, with similar 40% decrease in 24-hour integrated glucose and insulin levels, although gastric bypass led to rapid systemic appearance of ingested glucose with large early rise and subsequent fall in plasma glucose and insulin levels; the authors concluded that weight loss appears to underlie the effect of gastric bypass surgery. In an analysis of the relationship between resting heart rate (RHR) and the effect of dopamine agonist treatment on glycemia, 243 persons with RHR ≥ 70 receiving rapidly absorbed bromocriptine in the morning were compared with 129 receiving placebo, showing a significantly greater reduction in pulse with active treatment, which correlated with reduction in HbA1c, suggesting that elevated sympathetic nervous system tone, perhaps secondary to insulin resistance, is present in a subset of persons with type 2 diabetes and may be involved in the maintenance of hyperglycemia. In a meta-analysis of six randomized controlled trials of the dopamine agonist bromocriptine enrolling 3339 participants and of three trials of cabergoline 0.5 mg enrolling 117 participants, both led to similar 0.7% reduction in HbA1c; this class of agents may deserve greater use.