Short-term lifestyle intervention significantly increases fasting adiponectin and induces a decline in serum adiponectin during oral glucose tolerance test, without changes in insulin resistance

Abstract

Introduction: Metabolic syndrome is associated with insulin resistance (IR) and low concentrations of adiponectin, an adipocytokine that improves insulin sensitivity and has anti-inflammatory and anti-atherogenic properties. An increase in circulating adiponectin may, therefore, have beneficial effects in terms of reduction of cardiovascular risk. We aimed to establish whether short-term (two-week) lifestyle intervention alters serum concentrations of adiponectin, and whether there are changes in adiponectin during oral glucose tolerance test (OGTT). Material and methods: We measured adiponectin levels during 75.0 gram OGTT before and after two weeks of a hospital-based lifestyle modification programme that consisted of hypocaloric diet and moderate exercise in 16 severely obese, non-diabetic subjects (4 males), aged 42.0±14.18 years, BMI 42.65±7.82 kg/m2 (mean ±SD). IR indices were assessed before and after intervention. Results: Exercise and diet programme resulted in a decline of BMI (to 40.21±7.14 kg/m2, p<0.001) and fasting glucose (p=0.002), although without significant improvement in IR. There was, however, a significant rise in fasting adiponectin (from 32.1±13.2 nmol/l to 35.38±11.04 nmol/l, p=0.008). Furthermore, though initially there was no change in serum adiponectin levels during OGTT, there was a significant decline in serum adiponectin during OGTT at the end of the study (p<0.001). Conclusions: A two-week period of lifestyle modification (hypocaloric diet and moderate exercise) increases fasting adiponectin and induces a decline in serum adiponectin during OGTT in severely obese subjects. Favourable changes in serum adiponectin in subjects at high risk of cardiovascular disease are observed after a relatively short period and precede significant changes in insulin resistance.

Keywords

• adiponectin
• oral glucose tolerance test
• obesity
• metabolic syndrome