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Sympathovagal imbalance in type 2 diabetes more intense among male relatives
Among first-degree relatives of patients with type 2 diabetes, sympathovagal imbalance is more severe in males, linking them to increased cardiovascular risk as a result of dyslipidemia, inflammation and oxidative stress in this population, according to study data.
Researchers of the cross-sectional study recruited 226 medical students from the Jawaharlal Institute of Postgraduate Medical Education and Research in Puducherry, India. The study participants were placed into one of four categories: control group women (n=65), control group men (n=60), study group women (n=52) and study group men (n=49). The control groups consisted of healthy participants with no family history of diabetes, whereas study groups consisted of healthy participants with first-degree relatives who have type 2 diabetes.
All participants underwent BMI measurement, blood pressure variability tests, including baroreflex sensitivity, heart rate variability, insulin resistance, lipid profile, inflammatory marker testing and oxidative stress marker testing.
The researchers found that compared with the study group women, study group men had significantly higher measurements of the following: BMI, heart rate, left ventricular ejection time, cardiac output, total peripheral resistance, homeostasis model assessment of insulin resistance (HOMA-IR), lipid profile, inflammatory and oxidative stress markers, and ratio of low-frequency to high-frequency power of heart rate variability (LF-HF ratio), which is considered a sensitive marker of sympathovagal imbalance (SVI). The study group men also had lower baroreflex sensitivity than study group women. SVI occurred with greater intensity in the study group men; this was caused by increased sympathetic tone and decreased vagal tone. SVI did not occur in the control groups.
A multiple regression analysis revealed that LF-HF ratio was independently influenced by BMI, HOMA-IR, inflammatory and oxidative stress markers, and baroreflex sensitivity. Logistic regression analysis determined that LF-HF, which was higher in men, was significantly predictive of prehypertension and rate pressure product, which are markers of CV risk.
The researchers said obesity, which is known to be linked to type 2 diabetes, did not appear to influence the incidence of SVI in relatives of patients with diabetes.
“Obesity is prevalent in offspring with family history of diabetes,” the researchers wrote. “Although BMI was significantly increased in women vs. men in the study group, BMI had independent contribution to LF-HF ratio in men but not women. Thus, increased adiposity does not appear to be directly linked to SVI in these subjects.”
Disclosure: The researchers report no relevant financial disclosures.