25-Hydroxyvitamin D Concentration and Sleep Duration and Continuity: Multi-Ethnic Study of Atherosclerosis.

STUDY OBJECTIVES: To determine the associations of 25-hydroxyvitamin D (25(OH)D) concentration with sleep continuity, quality, and symptoms, and to explore race/ethnic variation.

DESIGN: Cross-sectional study.

SETTING: Multi-Ethnic Study of Atherosclerosis (MESA).

PARTICIPANTS: There were 1,721 adults.

MEASUREMENTS AND RESULTS: Sleep outcomes were measured by polysomnography, actigraphy, and questionnaires. Serum 25(OH)D concentration was expressed by clinical thresholds (< 20, 20-29, ≥ 30 ng/mL) and continuously. Using linear regression, we determined the associations between 25(OH)D concentration and sleep duration, efficiency, and symptoms, and assessed race/ethnic variation. Mean age was 68.2 ± 9.1 y, and 37.2% were white, 27.7% African American, 11.9% Chinese Americans, and 23.2% Hispanic. Mean 25(OH)D concentration was 25.4 ± 10.5 ng/mL. 25(OH)D deficient participants had the shortest sleep duration, lowest sleep efficiency, and highest sleepiness scores. After adjusting for demographics, obesity, and health habits, deficient individuals slept an average of 13.0 min (95% confidence interval, -22.8, -3.2) shorter than sufficient individuals. Race/ethnic-stratified analyses indicated that the strongest associations were in African Americans, in whom adjusted sleep duration was 25.6 ± 11.7 min shorter in deficient versus sufficient individuals (P = 0.04), and in Chinese Americans, adjusted apnea-hypopnea index (AHI) was 7.5 ± 3.3 events/h higher in deficient versus sufficient individuals.

CONCLUSION: Overall, there were modest associations between 25-hydroxyvitamin D (25(OH)D) concentration and sleep traits. However, race-stratified analyses suggested the association between 25(OH)D concentration and sleep traits varied by race/ethnicity. Vitamin D deficiency was most strongly associated with short sleep duration in African Americans and with elevated apnea-hypopnea index in Chinese Americans, suggesting that race/ethnicity may modify these associations.