Sympathovagal imbalance contributes to prehypertension status and cardiovascular risks attributed by insulin resistance, inflammation, dyslipidemia and oxidative stress in first degree relatives of type 2 diabetics.

BackgroundThough cardiovascular (CV) risks are reported in first-degree relatives (FDR) of type 2 diabetics, the pathophysiological mechanisms contributing to these risks are not known. We investigated the association of sympathovagal imbalance (SVI) with CV risks in these subjects.Subjects and methodsBody mass index (BMI), basal heart rate (BHR), blood pressure (BP), rate-pressure product (RPP), spectral indices of heart rate variability (HRV), autonomic function tests, insulin resistance (HOMA-IR), lipid profile, inflammatory markers, oxidative stress (OS) marker, rennin, thyroid profile and serum electrolytes were measured and analyzed in subjects of study group (FDR of type 2 diabetics, n = 72) and control group (subjects with no family history of diabetes, n = 104).ResultsBMI, BP, BHR, HOMA-IR, lipid profile, inflammatory and OS markers, renin, LF-HF (ratio of low-frequency to high-frequency power of HRV, a sensitive marker of SVI) were significantly increased (pConclusionSVI in FDR of type 2 diabetics occurs due to sympathetic activation and vagal withdrawal. The SVI contributes to prehypertension status and CV risks caused by insulin resistance, dyslipidemia, inflammation and oxidative stress in FDR of type 2 diabetics

Multiple regression analysis of LF-HF (as dependent variable) with various parameters (as independent variables) in study group subjects.

<p>P values<0.05 considered significant. BMI: Body mass index; HOMA-IR: homeostatic model assessment of insulin resistance; AI: Atherogenic index; IL6: Interleukin 6; hsCRP: high-sensitive C reactive protein; TNFα: Tumor necrosis factorα; TBARS: Thiobarbituric acid reactive substance; PHTN status: Prehypertension status.</p

Bivariate logistic regression analysis of RPP (as dependent variable) with LF-HF ratio of heart rate variability (as independent variable) in control group and study group subjects after adjusting for BMI.

<p>p<0.05 considered significant; OR : odds ratio; RPP: rate pressure product; LF-HF: Ratio of low-frequency to high-frequency power of heart rate variability; C.I. : confidence interval.</p

Correlation of LF-HF with various parameters in both the groups.

<p>The p value <0.05 was considered significant. BMI: Body mass index; BHR: Basal heart rate; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; MAP: Mean arterial pressure; RPP: Rate-pressure product; HOMA-IR: homeostatic model assessment of insulin resistance; TC: Total serum cholesterol; TG: Triglyceride; LDL: Low-density lipoprotein; HDL: High-density lipoprotein; IL6: Interleukin 6; hsCRP: high-sensitive C reactive protein; TNFα: Tumor necrosis factor α; TBARS: Thiobarbituric acid reactive substance.</p