Associations Between the Prevalence of Metabolic Syndrome and Sleep Parameters Vary by Age

Causal relationship of sleep duration on risks for metabolic syndrome: a Mendelian randomization study

BACKGROUND

The cluster of cardiovascular risk factors, referred to as metabolic syndrome (MetS), represents a substantial risk factor for cardiovascular diseases and presents a significant public health challenge. However, previous epidemiological investigations exploring the link between sleep duration and MetS lack experimental evidence to establish a causal relationship. Hence, he objective of this study is to examine the association between sleep duration and MetS by employing the Mendelian randomization (MR) approach.

METHODS

A cross-sectional study was conducted utilizing the Taiwan Biobank database, which comprised 33,270 predominantly Han Chinese individuals aged 30-70 years with no history of cancer and enrolled between 2008 and 2020. This study was conducted using Taiwan Biobank database. In MR analysis, we constructed weighted and unweighted genetic risk scores by calculating the SNP alleles significantly associated with sleep duration. Two-stage regression analysis was used to estimate odds ratio (OR) and 95% confidence interval (CI).

RESULTS

In the observational epidemiologic study, after multivariate adjustment, the OR for sleep durations of < 5, 8-9 and > 9 h compared to those with a sleep duration of 7 h were 1.23 (95% CI: 1.07, 1.43), 1.15 (95% CI: 1.06, 1.24) and 1.84 (95% CI: 1.43, 2.36), respectively. In the MR analyses after multivariate adjustment, the ORs of MetS per 1 standard deviation increase in the estimated sleep duration and the probability of long and short sleep durations derived from weighted genetic risk scores were 0.64 (95% CI: 0.63, 0.66), 1.55 (95% CI: 1.51, 1.59), and 1.66 (95% CI: 1.62, 1.70), respectively.

CONCLUSIONS

Observational and MR analyses demonstrated that short and long sleep durations are potential causal risk factors for MetS. Therefore, long and short sleep durations should be considered as risk factors in MetS-prevention strategies.

Habitual Sleep Duration and Health-Related Quality of Life in Family Caregivers: Findings from the Behavioral Risk Factor Surveillance System

BACKGROUND

Insufficient sleep duration is associated with poor health-related quality of life (HRQoL). However, this relationship has not been studied in family caregivers, a group at high risk of insufficient sleep duration and poor HRQoL.

OBJECTIVE

To examine the associations between habitual sleep duration and HRQoL measures in family caregivers.

METHODS

This cross-sectional study used data from 23,321 caregivers in the 2016 Behavioral Risk Factor Surveillance System. The HRQoL measures were health status and poor mental and physical health days. A multivariable logistic regression model was used to assess the association between sleep duration (<7, 7-9, >9 hours) and health status (fair or poor versus good to excellent). Zero-inflated negative binomial models were used to analyze the association of sleep duration with poor mental and physical health days.

RESULTS

Fair or poor health status was significantly higher in caregivers with short (odds ratio [OR], 1.40; 95% CI: 1.12, 1.74) and long (OR, 2.07; 95% CI: 1.34, 3.21) sleep duration. Short sleep duration was associated with a higher number of poor mental health days (IRR [incident rate ratio], 1.17; 95% CI: 1.04, 1.31) and poor physical health days (IRR, 1.26; 95% CI: 1.10, 1.45). Long sleep duration was associated with more poor mental health days (IRR, 1.31; 95% CI: 1.08, 1.60).

CONCLUSION

Extremes in sleep duration were associated with lower HRQoL. These findings point to the need for interventions that promote adequate sleep and address factors underlying extremes in sleep duration in the context of family caregiving.

Sleep duration and metabolic syndrome: An updated systematic review and meta-analysis

We examined the association between self-reported sleep duration and metabolic syndrome (MetS). Data were collected from 36 cross-sectional and 9 longitudinal studies with a total of 164,799 MetS subjects and 430,895 controls. Odds ratios (ORs) for prevalent MetS and risk ratios (RRs) for incident MetS were calculated through meta-analyses of adjusted data from individual studies. Short sleep duration was significantly associated with increased prevalent MetS (OR = 1.11, 95% CI = 1.05-1.18) and incident MetS (RR = 1.28, 95% CI = 1.07-1.53) in cross-sectional and longitudinal studies, respectively. Furthermore, long sleep duration was significantly associated with increased prevalent MetS in cross-sectional studies (OR = 1.14, 95% CI = 1.05-1.23), but not incident MetS (RR = 1.16, 95% CI = 0.95-1.41) in longitudinal studies. Interestingly, the association between long sleep and prevalent MetS was found in sleep duration defined by 24-h sleep (including naps) rather than nighttime sleep. Our findings suggest 1) a "U-shape" relationship between sleep duration and MetS in cross-sectional studies and 2) association between short sleep duration, but not long sleep duration with incident MetS. Future studies should shed light on the underlying mechanisms related to the association between sleep duration and MetS and examine if normalizing sleep duration reduces MetS risk in the general population.

Sleep Duration and the Risk of Metabolic Syndrome in Adults: A Systematic Review and Meta-Analysis

Objective: Epidemiological studies have reported inconsistent findings for the association between sleep duration and metabolic syndrome. We aimed to clarify the effects of short and long sleep durations on metabolic syndrome in adults by performing a meta-analysis. Methods: Adopting random-effects models, this study analyzed the effects of short and long sleep durations based on data from prospective cohort studies and cross-sectional studies retrieved from four electronic databases from inception to May 2020. Results: We collected data from 235,895 participants included in nine prospective cohort studies and 340,492 participants included in 27 cross-sectional studies. In cohort studies, short sleep duration was associated with an increased risk of metabolic syndrome (RR, 1.15; 95% CI, 1.05-1.25, I 2 = 63.1%, P < 0.001) compared with normal sleep duration. While long sleep duration was not associated with new-onset metabolic syndrome (RR, 1.02, 0.85-1.18, I 2 = 38.0%, P = 0.491). In cross-sectional studies, both short (OR, 1.06, 95% CI, 1.01-1.11, I 2 = 66.5%, P < 0.001) and long (OR, 1.11, 95% CI, 1.04-1.17, I 2 = 73.8%, P < 0.001) sleep durations were associated with a high prevalence of metabolic syndrome. Conclusions: Only a short sleep duration was associated with an increased risk of metabolic syndrome. Future studies should address whether the association is casual and modifiable.

Longitudinal association between sleep and 5-year incident metabolic syndrome in older Chinese adults: a community-based cohort study

PURPOSE

Our aim was to investigate the association between sleep and the development of metabolic syndrome (MetS) in Chinese older adults and to accumulate evidence for the prevention of MetS through sleep management.

METHODS

This prospective study followed 3005 participants aged over 60 derived from the Weitang Geriatric Diseases Study who were without MetS at baseline. MetS was defined according to the Adult Treatment Panel III (ATP III) criteria. Logistic regression models were fit to assess the association between sleep and MetS incident and a linear regression model was used to examine the impact of sleep duration on every component of MetS. Data on sleep-related parameters were obtained based on a self-reported questionnaire.

RESULTS

After five-year follow-up, 13.51% participants developed MetS, of which 46.86% were women. The incidence of MetS was highest among adults who slept 6 h or less and lowest among those who slept 7 h after adjusted for multiple variables. Subgroup analyses showed no gender specificity. The variation of fasting plasma glucose (FBG) for ≥9 h per night was significantly lower than that for 7.01-7.99 h per night (β = -0.18, P < 0.05). Sleeping for 8-8.99 h also decreased the variation of diastolic blood pressure (DBP) compared to 7.01-7.99 h (β = -0.84, P < 0.05).

CONCLUSION

We conclude that both short and long sleep duration are risk factors for MetS incident in older adults.

The Association Between Sleep and Metabolic Syndrome: A Systematic Review and Meta-Analysis

PURPOSE

Sleep duration is thought to play a key role in the development of metabolic syndrome. However, the results have been inconsistent.

METHODS

We conducted a systematic review and meta-analysis of cohort studies and searched publications in PubMed, Embase, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov. The summary relative risks (RRs) were estimated using a random model. The sensitivity analysis was performed by sequentially excluding each study to test the robustness of the pooled estimates.

FINDING

We included 13 studies involving 300,202 patients in which short sleep and long sleep significantly increased the risk of metabolic syndrome 15% (RR = 1.15, 95%CI = 1.09-1.22, p < 0.001) and 19% (RR = 1.19, 95%CI = 1.05-1.35, p < 0.001). Moreover, the relationship between sleep duration and metabolic syndrome risk presented a U-shaped curve. Short and long sleep increased the risk of obesity by 14% (RR = 1.14, 95%CI = 1.07-1.22, p<0.001) and 15% (RR = 1.15, 95%CI = 1.00-1.30, p = 0.04), and high blood pressure 16% (RR = 1.16, 95%CI = 1.02-1.31, p = 0.03) and 13% (RR = 1.13, 95%CI = 1.04-1.24, p = 0.01), respectively. Short sleep can potentially increase the risk of high blood sugar by 12% (RR = 1.12, 95%CI = 1.00-1.15, P = 0.05).

IMPLICATIONS

Based on our findings, sleep is a behavior that can be changed and is economical. Clinically doctors and health professionals should be encouraged to increase their efforts to promote healthy sleep for all people.

Association between sleep duration and executive function differs between diabetic and non-diabetic middle-aged and older adults

Executive function is defined as a set of cognitive skills that are necessary to plan, monitor, and execute a sequence of goal-directed complex actions. Executive function is influenced by a variety of factors, including habitual sleep duration and diabetes. In the present study, we investigated in 18,769 Swedish adults (mean age: 61 y) the association between executive function, diabetes, and self-reported sleep duration. We observed a significant interaction between diabetes and sleep duration for the Trail Making Test (TMT) ratio (P < 0.01). This ratio is a measure of executive function where higher values indicate worse performance. Among diabetic participants (n = 1,523), long (defined as ≥9 h per day) vs. normal sleep duration (defined as 7-8 hours per day) was associated with a higher TMT ratio (P < 0.05). Similar significant results were observed in diabetic individuals without pharmacological treatment for diabetes (n = 1,062). Among non-diabetic participants (n = 17,246), no association between long sleep duration and the TMT ratio was observed (P > 0.05). Instead, short (defined as <7 h per day) vs. normal sleep duration was linked to a higher TMT ratio (P < 0.05). These findings suggest that the association between sleep duration and executive function differs between diabetic and non-diabetic middle-aged and older adults. Based on the cross-sectional design of the study, no firm conclusions can be drawn on the causality of the relations.

Associations of sleep durations and sleep-related parameters with metabolic syndrome among older Chinese adults

PURPOSE

There is a lack of data on the role of sleep in the development of metabolic syndrome (MetS) in older adults. We aimed to examine the associations of sleep durations at night and other sleep-related parameters with the presence of MetS in older Chinese adults.

METHODS

Data of 4579 individuals aged 60 years or older from the Weitang Geriatric Disease Study were analyzed. MetS was diagnosed based on the Adult Treatment Panel III (ATP III) criteria. Information regarding sleep durations and other sleep-related parameters was collected by questionnaires.

RESULTS

Compared with those with daytime napping, individuals without daytime napping were at an increased risk of MetS (odds ratio [OR] = 1.23; 95% confidence interval [CI] = 1.03-1.47). Each hour increase in daytime napping increased the risk of MetS by 33% (OR = 1.33; 95% CI = 1.15-1.52). After adjusting for the effect of age and gender, a J-shaped association between sleep durations at night and the presence of MetS was observed. The risk of MetS was lowest among those who slept 7-8 h at night. Gender-stratified analysis indicated that the J-shaped relationship between sleep durations at night and MetS remained significant in men but not in women.

CONCLUSIONS

In older Chinese adults, sleep durations at night might have a dual effect on the risk of MetS and this effect was particularly pronounced in men. The results indicated that circadian rhythm might play an important role in the development of MetS in older populations.

Sleep problems are a strong predictor of stress-related metabolic changes in police officers. A prospective study

OBJECTIVE

Previous studies have shown that workers chronically exposed to occupational stress have an increased risk of metabolic syndrome (MetS) and sleep problems (SPs). The purpose of this study was to verify whether SPs mediate the relationship between stress and MetS.

METHOD

A 5-year prospective cohort study included 242 police officers from a rapid response unit engaged exclusively in maintaining law and order. Perceived stress levels were measured repeatedly with the demand-control-support and the effort-reward-imbalance questionnaires; insomnia symptoms were assessed with the Pittsburgh Sleep Quality Index; excessive daytime sleepiness was measured using the Epworth Sleepiness Scale. MetS and its components were evaluated at baseline and at follow-up.

RESULTS

During 5-year follow-up period, 26 new cases of MetS were identified. Both occupational stress and SPs were significantly related to incident cases of MetS. Insomnia symptoms showed a highly significant association with MetS (aOR 11.038; CI95% 2.867-42.493). Mediation analysis confirmed that SPs mediate the relationship between stress and MetS. A reciprocal relationship was found between job stress and SPs. Work-related stress was a significant predictor of insomnia symptoms, short sleep duration, sleep dissatisfaction, and sleepiness. Compared to the reference group, police officers with SPs at baseline had significantly higher odds of reporting high stress at follow-up.

CONCLUSION

SPs play a mediating role in the relationship between occupational stress and MetS. Prevention of MetS must include the control of stress factors and an increase in the resilience of workers, but correct sleep hygiene is also an essential factor.

Lack of association between self-reported insomnia symptoms and clamp-derived insulin sensitivity in elderly men

Insomnia-related sleep disruptions, such as short and disturbed sleep, have been tied to systemic insulin resistance in young adult populations. We therefore sought to confirm these findings in a cohort of elderly men. To this aim, we utilized variables from 980 men who participated in the investigation at age 70 of the Uppsala Longitudinal Study of Adult Men. Self-reported insomnia symptoms were assessed by questions about difficulty initiating sleep, early final awakening, and regular use of hypnotics. All participants also underwent the gold-standard hyperinsulinemic-euglycemic clamp technique to assess the insulin sensitivity index (M/I). Finally, fasting blood was collected to measure free fatty acids (FFAs) and adiponectin. Differences in blood parameters between men with and those without insomnia were determined by ANCOVA, and were adjusted for lifestyle and cardio-metabolic risk factors. Our analysis yielded no differences in M/I, FFAs, and adiponectin between men with and those without insomnia symptoms. Analyses in non-diabetic and diabetic subsamples confirmed these negative findings. Our cross-sectional results therefore suggest that insomnia symptoms may have a minimal effect, if any, on measures of insulin sensitivity in elderly men. Given the observational design of our study, future studies are needed to determine whether experimental sleep manipulations influence systemic insulin sensitivity in elderly humans, as has previously been shown in young adult populations.