Sleep duration, sleep quality, and biomarkers of inflammation in a Taiwanese population.

PURPOSE

Short and long sleep duration and sleep quality are associated with health including all-cause mortality, cardiovascular disease, diabetes, and obesity. Inflammation may play a role in mediating these associations.

METHODS

We examined associations between inflammation and self-reported sleep characteristics in 1020 respondents of the 2000 and 2006 Social Environment and Biomarkers of Aging Study, a nationally representative survey of Taiwanese adults ages 53 and over. Regression models were used to estimate cross-sectional relationships between inflammation (interleukin-6, C-reactive protein, fibrinogen, e-selectin, soluble intercellular adhesion molecule-1, albumin, and white blood cell count) and a modified Pittsburgh Sleep Quality Index, index subcomponents, and self-reported sleep duration. Change in inflammatory markers between 2000 and 2006 was also used to predict long or short sleep duration in 2006.

RESULTS

Inflammation was not related to the overall index of sleep quality. However, longer sleep (>8 hr) was associated with higher levels of inflammation. These associations remained after adjustment for waist circumference, self-reported health decline, diabetes, arthritis/rheumatism, heart disease, and depressive symptoms. Increases in inflammation between 2000 and 2006 were associated with long but not short sleep duration in 2006 for several markers.

CONCLUSIONS

Long sleep duration may be a marker of underlying inflammatory illness in older populations. Future studies should explore whether inflammation explains observed relationships between long sleep and mortality.