Self-reported sleep duration and napping, cardiac risk factors and markers of subclinical vascular disease: Cross-sectional study in older men

This cross-sectional study investigated the association between daytime and night-time sleep patterns and cardiovascular risk markers in 1722 surviving males aged 71–92 years who participated in the British Regional Heart Study conducted in 1978–1980. Included subjects were assessed for cardiovascular disease risk factors; this included measurement of FEV1 using the Vitalograph COMPACT spirometer.