Visceral abdominal fat was strongly negatively correlated with insulin sensitivity (r = -0.93, p < 0.001) and positively associated with resting heart rate (r = 0.70, p = 0.003).
Case-Control (n=30)
Is visceral adiposity associated with insulin resistance and autonomic nervous system dysregulation in subjects with and without a family history of type 2 diabetes?
Visceral adiposity is strongly associated with insulin resistance and autonomic imbalance (high sympathetic/parasympathetic ratio), suggesting a mechanistic link that may be partly independent of genetic background.
Absolute Event Rate: 9.2% vs 10.3%
p-value: p=not significant
OBJECTIVE: To evaluate the interplay among abdominal adipose tissue distribution, the cortisol axis, the autonomic nervous system, and insulin resistance. RESEARCH METHODS AND PROCEDURES: Two age-, sex-, and BMI-matched groups were studied. Fifteen subjects were first-degree relatives of patients with type 2 diabetes (R), and 15 had no family history of diabetes (controls, C). A hyperinsulinemic euglycemic clamp, cortisol measurements, and analysis of heart rate variability (HRV) were performed. Computed tomography was performed in a subgroup (n = 9 + 9) to determine abdominal adipose tissue distribution. RESULTS: R tended to be less insulin-sensitive than C (M value 9.2 +/- 1.0 vs 10.3 +/- 0.7 mg/kg per minute, not significant). Stimulation with tetracosactin or corticotropin releasing hormone yielded lower peak serum cortisol levels in R (p = 0.03 and p = 0.06, respectively). The amount of visceral abdominal fat (VAT) tended to be greater in R. In all subjects, VAT was negatively correlated to insulin sensitivity (r = -0.93, p < 0.001). There was a positive association between VAT and resting heart rate (r = 0.70, p = 0.003) and sympathetic/parasympathetic ratio in HRV assessment after tilt (r = 0.53, p = 0.03). Subcutaneous abdominal tissue was not associated with insulin sensitivity or any of the hormonal or HRV assessments. DISCUSSION: Subjects genetically predisposed for type 2 diabetes had a tendency toward a larger amount of VAT and to lower insulin sensitivity compared with control subjects. The amount of visceral fat was strongly associated with insulin resistance and signs of a high ratio of sympathetic vs. parasympathetic reactivity. A large amount of visceral fat may act in concert with sympathetic/parasympathetic imbalance to promote the development of insulin resistance, and this may be partly independent of genetic background.
Lindmark et al. (2005) conducted a case-control in Insulin resistance risk (n=30). Family history of type 2 diabetes vs. No family history of diabetes was evaluated on Insulin sensitivity (M value) (p=not significant). Visceral abdominal fat was strongly negatively correlated with insulin sensitivity (r = -0.93, p < 0.001) and positively associated with resting heart rate (r = 0.70, p = 0.003).