Sleep Duration and Metabolic Syndrome. An Updated Dose–Risk Metaanalysis

Abstract

Rationale: Several studies have reported that both short and long sleep durations are associated with the metabolic syndrome, but whether a dose-response relationship exists is unclear.Objectives: We performed a metaanalysis to study the magnitude of the association between the different durations of sleep and metabolic syndrome. Methods:We searched in the databases of PubMed, Web of Science, and Ovid (all Journals@Ovid) from inception to October 4, 2014 for cross-sectional studies where an association between metabolic syndrome and sleep duration was analyzed. Measurements and Main Results:Eighteen studies with 75,657 participants were included. Daily sleep duration of 7 to 8 hours was used as the reference group. The odds ratio (OR) of having metabolic syndrome for short (,7 h) sleep was 1.23 (95% CI, 1.11-1.37; P , 0.001; I 2 , 71%). The ORs for less than 5 hours, 5 to 6 hours, and 6 to 7 hours of sleep were 1.51 (95% CI, 1.10-2.08; P = 0.01), 1.28 (95% CI, 1.11-1.48; P , 0.001), and 1.16 (95% CI, 1.02-1.31; P = 0.02), respectively. The coefficient of sleep duration on log of ORs was 20.06 6 0.02 (P = 0.02). The OR for long sleep duration was 1.13 (95% CI, 0.97-1.32; P = 0.10; I 2 , 89%).Conclusions: A dose-response relationship exists between short sleep duration and metabolic syndrome. Those who report a sleep duration of less than 5 hours have a 1.5 higher odds of having metabolic syndrome. Our study does not support the notion that long sleep is associated with metabolic syndrome.

Role of sleep quality in the metabolic syndrome

“…Interestingly, one study found that after adjusting for confounders, long (≥9 hours) but not short (<6 hours) sleep duration was associated with an increased risk of the MetS 76. A recent meta-analysis of 18 studies encompassing 75,657 participants and using adults sleeping for 7–8 hours as a reference group found a dose–response relationship between sleep duration and the MetS, with increasing risk of the MetS in sleep categories all the way up to a 1.5-fold OR (95% CI 1.1–2.08, P =0.01) among those sleeping for <5 h/night; however, they did not find a significant association between long sleep duration and the MetS – OR 1.13 (95% CI, 0.97–1.32; P =0.10) 71. The question of causality is difficult to assess in cross-sectional studies; however, a prospective cohort study of 2,579 adults aged 40–70 years without MetS at baseline, who were followed for an average of 2.6 years, found a significantly higher risk of incident MetS for those sleeping for <6 hours – adjusted OR (95% CI) 1.41 (1.06–1.88).…”

Sleep duration and the risk of metabolic syndrome – a cross-sectional study

“…The results of the conducted tests show no dependency between short sleep duration (≤ 6 h) and the risk of MetS, despite the fact that many authors have confirmed the presence of such dependencies [9, 12-15, 21, 32]. It should be mentioned, however, that most of these papers applied different definitions of MetS [9,[12][13][14]32], and in some there were also definitions of short sleep duration applied which was less than 6 h per night [15,21]. Long sleep duration (≥ 9 h) was connected with a higher risk of MetS, but only in the unadjusted model.…”

“…Some of them show a U-shaped relationship between sleep duration and the prevalence of MetS [10]. It has been shown in some papers that MetS is only associated with short sleep duration [12][13][14][15] or long sleep duration [16][17][18]. In another paper, however, there was no relationship found between sleep duration and the risk of MetS [19].…”

The Prevalence and Associated Factors of the Metabolic Syndrome in Pre-menopausal Housewives: An Analysis of the 2010~2015 Korean National Health and Nutrition Examination Survey

“…대사증후군의 위험인자는 연령, 유전, 폐경상태, 인종, 비만, 흡연, 소득, 탄수화물 섭취량, 신체활동 [8], 고혈압 등의 가족력 [9], 지각된 스트레스, 우울, 자살생각 및 수면시간 등의 정신심 리적 요인 [10], 백혈구와 적혈구수 [11] 등으로 알려져 있다. 수 면부족은 탄수화물 식품에 대한 식욕을 증진시키고 인슐린 저 항성을 높여 대사증후군의 발생 위험을 높이며 [10], 우울 등의 정신심리적 요인은 좋지 않은 식습관, 수면 장애, 신체활동 저 하 등과 관련되어 대사증후군의 발생 위험을 높이는 것으로 보 고되고 있다 [12].…”

“…수 면부족은 탄수화물 식품에 대한 식욕을 증진시키고 인슐린 저 항성을 높여 대사증후군의 발생 위험을 높이며 [10], 우울 등의 정신심리적 요인은 좋지 않은 식습관, 수면 장애, 신체활동 저 하 등과 관련되어 대사증후군의 발생 위험을 높이는 것으로 보 고되고 있다 [12]. 백혈구와 적혈구 수의 증가 또한 인슐린 저항 상태와 관련되어 대사증후군 발생 위험을 증가시키는 경향이 있다 [11].…”