Contribution of insulin resistance to decreased baroreceptor sensitivity & cardiometabolic risks in pre-obesity & obesity

BACKGROUND & OBJECTIVES: Although insulin resistance (IR) is a known complication in obesity, the physiological mechanisms linking IR with cardiometabolic risks in obesity have not been well studied. This study was conducted to assess the difference in cardiovascular (CV) risk profile in IR and non-IR (NIR) conditions, and contribution of IR to cardiometabolic risks in pre-obese and obese individuals. METHODS: Basal CV, blood pressure variability, autonomic function test and cardiometabolic parameters were recorded in pre-obese (n=86) and obese (n=77) individuals during 2012 and 2015. The association of altered cardiometabolic parameters with homeostatic model for IR (HOMA-IR) in pre-obese and obese groups and with baroreceptor sensitivity (BRS) in IR and NIR groups was calculated by appropriate statistical analysis. RESULTS: Decreased BRS, a known CV risk and cardiometabolic parameters were significant in IR (pre-obese and obese) group compared to the NIR group. Sympathovagal imbalance in the form of increased sympathetic and decreased parasympathetic activities was observed in individuals with IR. There was no significant difference in the level of independent contribution of HOMA-IR to cardiometabolic parameters in pre-obese and obese groups. Adiponectin and inflammatory markers had an independent contribution to BRS in IR group. INTERPRETATION & CONCLUSIONS: Findings of the present study demonstrated that the intensity of cardiometabolic derangements and CV risk were comparable between IR, pre-obese and obese individuals. Pro-inflammatory state, dyslipidaemia and hypoadiponectinaemia might contribute to CV risk in these individuals with IR. IR could possibly be the link between altered metabolic profile and increased CV risks in these individuals independent of the adiposity status.