Obesity, high-sensitive C-reactive protein and snoring in older Chinese: the Guangzhou Biobank Cohort Study

abitual snoring and elevated high-sensitive C-reactive protein (HsCRP) have both been associated with increased risk of cardiovascular disease. However, snoring and HsCRP are elevated in obese states which may thus be the primary determinant of both. We therefore investigated whether snoring may mediate the increased vascular risk directly through increased inflammation as indicated by HsCRP levels or if other determinants predominated in a large older Chinese population.

A total of 2508 males and 5709 females aged 50-85 years received a medical check-up including measurement of blood pressure, obesity indices, fasting total, LDL-, HDL-cholesterol, triglycerides, glucose and HsCRP. Information on self-reported snoring status was collected by standardized interview.

The age-adjusted geometric mean HsCRP concentrations increased significantly with higher snoring frequency in both genders (linear trend, p=0.02 for men and p<0.001 for women), but the association was no longer significant after controlling for waist and BMI. Furthermore, HsCRP levels were not significantly associated with snoring frequency groups stratified by BMI/waist quintiles in both genders, except for the 4th waist quintile in men. No interaction was observed between snoring and BMI/waist on HsCRP levels. The multivariate analysis showed that, in both genders, obesity, but not HsCRP, was associated with snoring.

Our results showed that snoring frequency did not have an independent effect on inflammation after adjusting for adiposity, and may thus contribute to vascular disease through alternative mechanisms.