Abstract

The insulin-sensitising adipose hormone adiponectin is reduced in type 2 diabetic patients. We assessed the relationships between plasma adiponectin and chronic hyperglycaemia. Adiponectin levels and glycated haemoglobin (HbA_1c) were measured at enrolment and after 90 days in 16 patients with type 2 diabetes aged (mean ± SEM) 63.0±0.6 years, with body mass index (BMI) 30.2±0.5 kg/m² and HbA_1c concentration 7.4± 0.1%, who did not modify their hypoglycaemic treatment during the observation period. Furthermore, plasma adiponectin was measured in 29 adult patients with type 1 diabetes and compared with 29 control subjects matched for sex, age, BMI, waist circumference and bioimpedance-estimated fat mass. In type 2 diabetic patients at enrolment, adiponectin concentration correlated with BMI (r = −0.46; p < 0.05), but not with HbA_1c. During the prospective observation, variations of adiponectin showed a significant correlation with variations of BMI (r = −0.47; p < 0.01), but not with variations of HbA_1c concentration. These results were confirmed by multivariate analysis after adjustment for sex and age. Adiponectin levels in type 1 diabetic patients (380.8±13.7 ng/ml in women, 192.5±13.9 ng/ml in men) were significantly (p < 0.05) higher than in control subjects (277.6±11.0 ng/ml in women, 102.7±5.1 ng/ml in men); plasma adiponectin correlated significantly with BMI and waist circumference, but not with HbA_1c. In conclusion, the reduction of plasma adiponectin levels in type 2 diabetic patients does not appear to be determined by chronic hyperglycaemia. Adiponectin levels are increased in type 1 diabetes, but this phenomenon is not attributable to differences in nutritional status or body composition.l21