Sex difference in the association between habitual daytime napping and prevalence of diabetes: a population-based study

Association between napping and type 2 diabetes mellitus

As the incidence of type 2 diabetes mellitus (T2DM) is increasing rapidly and its consequences are severe, effective intervention and prevention, including sleep-related interventions, are urgently needed. As a component of sleep architecture, naps, alone or in combination with nocturnal sleep, may influence the onset and progression of T2DM. Overall, napping is associated with an increased risk of T2DM in women, especially in postmenopausal White women. Our study showed that napping >30 minutes (min) increased the risk of T2DM by 8-21%. In addition, non-optimal nighttime sleep increases T2DM risk, and this effect combines with the effect of napping. For nondiabetic patients, napping >30 min could increase the risks of high HbA1c levels and impaired fasting glucose (IFG), which would increase the risk of developing T2DM later on. For diabetic patients, prolonged napping may further impair glycemic control and increase the risk of developing diabetic complications (e.g., diabetic nephropathy) in the distant future. The following three mechanisms are suggested as interpretations for the association between napping and T2DM. First, napping >30 min increases the levels of important inflammatory factors, including interleukin 6 and C-reactive protein, elevating the risks of inflammation, associated adiposity and T2DM. Second, the interaction between postmenopausal hormonal changes and napping further increases insulin resistance. Third, prolonged napping may also affect melatonin secretion by interfering with nighttime sleep, leading to circadian rhythm disruption and further increasing the risk of T2DM. This review summarizes the existing evidence on the effect of napping on T2DM and provides detailed information for future T2DM intervention and prevention strategies that address napping.

Relationship between daytime napping with the occurrence and development of diabetes: a systematic review and meta-analysis

OBJECTIVE

To determine the relationship of napping with incident diabetes risk and glycaemic control in people with diabetes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE (PubMed), EMBASE, Web of Science and the Cochrane Library were searched for studies published from database inception to 9 May 2023.

ELIGIBILITY CRITERIA

Observational studies reporting the relationship of napping with diabetes or glycaemic control in patients with diabetes in adult populations were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently screened the literature, extracted data and assessed the quality of the included studies. The results were reported as ORs and 95% CIs, which were pooled by using fixed and random effects models, and subgroup analyses were performed. The Grading of Recommendations Assessment, Development and Evaluation method was used to assess the quality of the evidence.

RESULTS

Forty studies were included in our review. Habitual napping was associated with an increased diabetes risk (OR 1.20, 95% CI 1.14 to 1.27) and poor glycaemic control in patients with diabetes (OR 2.05, 95% CI 1.55 to 2.73). Nap durations less than 30 min were unrelated to diabetes (OR 1.05, 95% CI 0.97 to 1.14). Nap durations of 30-60 min were associated with diabetes risk (OR 1.09, 95% CI 1.02 to 1.17), but there were differences in the subgroup analysis results. Nap durations of more than 60 min significantly increased the risk of diabetes (OR 1.31, 95% CI 1.20 to 1.44).

CONCLUSIONS

Napping is associated with increased diabetes risk and poor glycaemic control, and future research will need to confirm whether there are sex and regional differences. Nap durations of more than 60 min significantly increases the risk of diabetes, and the relationship between nap duration and glycaemic control in patients with diabetes needs to be further explored in the future.

PROSPERO REGISTRATION NUMBER

CRD42021292103.

Fatty Liver Index and Its Association with 10-Year Atherosclerotic Cardiovascular Disease Risk: Insights from a Population-Based Cross-Sectional Study in China

This cross-sectional study aimed to investigate the association between non-alcoholic fatty liver disease (NAFLD) and atherosclerotic cardiovascular disease (ASCVD), a global public health concern. A total of 9044 out of 10,104 adults from Guangzhou, China, were included in the analysis. We utilized the fatty liver index (FLI), a noninvasive indicator of NAFLD, and the pooled cohort equations (PCE) based on the 2013 ACC/AHA Guideline, the China-PAR model, and the Framingham Risk Score to assess the 10-year ASCVD risk. The results demonstrated a significant association between FLI and 10-year ASCVD risk (p < 0.001). Adjusted for age, individuals with high FLI (≥60) had an odds ratio of 3.91 (95% CI 2.52-6.08) compared to those with low FLI (<30). These findings persisted after adjusting for metabolic indicators. Notably, this association was consistently observed across all three risk prediction models: the PCE model, the China-PAR model, and the Framingham Risk Score. In conclusion, our study provides evidence supporting FLI as a reliable indicator of increased 10-year ASCVD risk in Chinese NAFLD patients. FLI serves as a valuable marker for early detection of ASCVD, highlighting its potential in clinical practice for risk assessment and prevention strategies.

Daytime napping and cardiovascular risk factors, cardiovascular disease, and mortality: A systematic review

Associations between night sleep duration and cardiovascular risk factors in adults have been well documented. However, the associations for daytime napping remain unclear. In this review, six databases were searched for eligible publications to April 8, 2022. A total of 11 articles were identified for umbrella review on the association of daytime napping with diabetes, metabolic syndrome (MetS), cardiovascular disease (CVD), and mortality in adults, 97 for systematic review on the association with CVD and several CVD risk factors. Our umbrella review showed that the associations of daytime napping with diabetes, MetS, CVD, and mortality in most meta-analyses were mainly supported by weak or suggestive evidence. Our systematic review showed that long daytime napping (≥1 h/d) was associated with higher odds of several CVD risk factors, CVD, and mortality, but no significant association was found between short daytime napping and most of the abovementioned outcomes. Our dose-response meta-analyses showed that daytime napping <30 min/d was not significantly associated with higher odds of most CVD risk factors and CVD among young and middle-aged adults. However, among older adults aged >60 years, we observed significant dose-response associations of daytime napping with higher odds of diabetes, dyslipidemia, MetS, and mortality starting from 0 min/d.

Sex Differences in Depression and Sleep Disturbance as Inter-Related Risk Factors of Diabetes

Objectives

Previous studies identified depression and sleep disturbance as risk factors for diabetes. Sleep disturbance and depression are known to be inter-related. Further, women relative to men are more prone to depression. Here, we investigated how depression and sleep disturbance may jointly influence the risk of diabetes and the effects of sex on these influences.

Methods

Using the data of 21,229 participants from the 2018 National Health Interview Survey, we performed multivariate logistic regression with diabetes diagnosis as the dependent variable, sex, self-reported frequency of weekly depression and nightly sleep duration, and their interactions with sex as independent variables, and age, race, income, body mass index and physical activity as covariates. We employed Bayesian and Akaike Information criteria to identify the best model, evaluated the accuracy of the model in predicting diabetes using receiver operating characteristic analysis, and computed the odds ratios of these risk factors.

Results

In the two best models, depression frequency and sleep hours interact with sex in determining the diagnosis of diabetes, with higher depression frequency and nightly duration of sleep longer or shorter than 7 to 8 hours associated with higher likelihood of diabetes. The two models both predicted diabetes at an accuracy (area under the receiver operating characteristic curve) of 0.86. Further, these effects were stronger in men than in women at each depression and sleep level.

Conclusions

Depression and sleep inter-relatedly rather than independently contributes to diabetes. Depression and sleep hours associate with diabetes more significantly in men than in women. The current findings indicate a sex-dependent relationship between depression, sleep disturbance and diabetes risk and add to a growing body of evidence linking mental and physical health.

Daytime napping is associated with retinal microcirculation: a large population-based study in China

STUDY OBJECTIVES

To investigate the association between daytime napping and retinal microcirculation.

METHODS

This is a cross-sectional study from a prospective population-based cohort. 2,662 participants were recruited after quota sampling. Information on napping was collected through face-to-face interviews. Retinal vascular calibers (RVCs), including central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), and arterio-to-venous ratio (AVR), were obtained from fundus photography. Multivariate regression and restricted cubic spline curve were performed to determine the association between RVCs and daytime napping duration.

RESULTS

56.4% participants reported daytime napping regularly. Compared to no nap, daytime nap was related to higher CRAE, with nap duration of 0.5-1 h showing the most significant association. 0.5-1 h daytime nappers displayed an average of 4.18 µm (95% confidence interval [CI] 2.45-5.91, p < 0.001) wider CRAE than non-nappers after adjustment. No significant association was found between CRVE and daytime napping. Moreover, individuals with 0.5-1 h daytime napping had a lower risk for AVR reduction (odds ratio [OR] 0.70, 95% confidence interval [CI] 0.56-0.86, p = 0.001) than non-nappers. Similar association persisted in non-hypertensive population. Restricted cubic spline indicated a J-shaped relationship between AVR reduction and nap duration.

CONCLUSION

Retinal microcirculation was positively associated with self-reported 0.5-1 h daytime napping. Better indicators of retinal microcirculation were probably related to nap duration in a J-shaped manner. Also, the possibly beneficial role of 0.5-1 h daytime napping on retinal microcirculation might be independent of clinically diagnosed vascular diseases.

Association of Daytime Napping with chronic diseases among Tibetan people in China: a cross-sectional study

BACKGROUND

Obesity, diabetes, and hypertension, as three of the most prevalent chronic diseases, remain a daunting health challenge. However, to our knowledge, no study has made a thorough examination of the association between the three chronic diseases and daytime napping, a widely accepted behavior in many countries. This is especially necessary among Tibetan populations, whose lifestyles and health outcomes may be unique, yet patterns of chronic diseases and napping are under-examined. Thus, we sought to explore the aforementioned association in the Tibetan population of China.

METHODS

A total of 2902 participants aged 45-79 in 2019 were included. Multivariate logistic regressions were conducted in 2020. The sex disparity was examined through interaction and stratified analyses.

RESULTS

Hypertension (40.7%) was more prevalent than obesity (20.2%) and diabetes (21.6%). Comparing to non-nappers, those who napped were more likely to have any conditions (OR = 1.30, 95% CI = 1.04-1.62 for 1-59 min/day group and OR = 1.40, 95% CI = 1.10-1.80 for ≥60 min/day group). Participants who had 1-59 min/day of napping were more likely to develop obesity (OR = 1.37, 95% CI = 1.07-1.75), and ≥ 60 min/day of napping was associated with diabetes (OR = 1.33, 95% CI = 1.01-1.74). The interactions between napping and sex were not statistically significant in the models.

CONCLUSIONS

The study revealed napping was unfavorably associated with obesity, diabetes, and any conditions in Tibetan people living on the Tibetan Plateau. Future interventions regarding the three chronic diseases may pay more attention to napping.

TRIAL REGISTRATION

Not applicable.

Association between daytime napping and obesity in Chinese middle-aged and older adults

Background

No studies have assessed the association between daytime napping and obesity in China. The study aimed to examine the association between daytime napping and obesity among Chinese middle-aged and older adults, and to evaluate the difference between the aforementioned association in men and women.

Methods

Overall, 14 685 participants aged 45 years and older were included by using data from China Health and Retirement Longitudinal Study (CHARLS) in 2015. A multivariable logistic regression model was used to investigate the relationship between daytime napping and obesity after adjusting for potential confounders. Stratified analyses were performed to examine the association differences by sex. Besides, the Cochran-Armitage test for trend was used to detect if there was a significant dose-response relationship between daytime napping and obesity.

Results

The mean age of participants was 60.32, and the mean daytime napping duration was 38.97 minutes. In the sample, compared with no daytime napping group, the risks of being obese were higher in both moderate daytime napping group (1-60 minute/d) (odds ratio OR = 1.27, 95% confidence interval (CI) = 1.13-1.44) and extend long daytime napping group (>60 minute/d) (OR = 1.34, 95% CI = 1.15-1.56). In sex stratification, these significant correlations only existed in women but not in men. Compared with no daytime napping, women who napped 1-60 minute/d and over 60 minute/d were more likely to be obese (OR = 1.37, 95% CI = 1.18-1.59 and OR = 1.49, 95% CI = 1.23-1.81, respectively). Besides, the Cochran-Armitage trend test revealed that the prevalence rate of obesity increased as the daytime napping duration increased (P < 0.001).

Conclusions

The study established the relationship between daytime napping and obesity in a general Chinese population. The association, however, was only detected among women. Furthermore, there was a dose-response relationship between daytime napping and obesity among women. Future studies may verify this association by using a longitudinal design and focus on the mechanisms behind such association.

Association of gonadal hormones and sex hormone binding globulin with risk of diabetes: A cohort study in middle-aged and elderly Chinese males

AIM

Late-onset hypogonadism in men is related to the development of diabetes. The association of gonadal hormones, sex hormone binding globulin with diabetes has been studied in various studies. However, there is no cohort study on the relationship between gonadal hormone, sex hormone binding globulin and diabetes in Chinese. We aimed to provide an insight into the possible association in middle-aged and elderly Chinese males.

METHODS

We included a population sample of 673 subjects aged 40 years or older. Total testosterone (TT), sex hormone binding globulin (SHBG), follicle-stimulating hormone (FSH) and luteinising hormone (LH) were detected. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated to estimate insulin sensitivity. Diabetes was diagnosed according to the 2010 American Diabetes Association criteria.

RESULTS

With an average follow-up time of 3.2 ± 0.5 years, 9.8% of participants had developed diabetes. The prevalence of diabetes was decreased according to increasing SHBG quartiles (Q1:13.1%, Q2: 12.0%, Q3: 11.2%, Q4: 3.0%, P for trend < .0001) and TT (Q1:16.0%, Q2: 7.9%, Q3: 9.0%, Q4: 6.4%, P for trend < .0001). The ORs of diabetes for increasing SHBG quartiles were 4.52 (95% CI 1.40-14.57), 4.32 (95% CI 1.33-14.06), 3.89 (95% CI 1.21-12.50) and 1.00 (reference) respectively. But the odds of prevalent diabetes were not increased in different quartiles of TT, FSH and LH. In subgroup analyses, the relationship between SHBG and risk of incident diabetes was significantly increased in the population aged over 60, without insulin resistance and with eGFR < 90 mL/min per 1.73 m² .

CONCLUSIONS

Compared with gonadal hormones, a lower level of SHBG is independently associated with the risk of diabetes in middle-aged and elderly Chinese males.

Association of metabolic syndrome with the incidence of low-grade albuminuria: a cohort study in middle-aged and elderly Chinese adults

Background: Individuals with metabolic syndrome have elevated risks of micro- and macro-albuminuria as well as chronic kidney disease (CKD).

Objective: To assess the influence of metabolic abnormalities on the presence of low-grade albuminuria (below the threshold for microalbuminuria).

Design, participants, and main outcome measures: This community-based cohort study included 3,935 eligible individuals aged 40 years or older. The presence of low-grade albuminuria was detected in those without micro- or macro-albuminuria and analyzed according to the highest quartile of the baseline urinary albumin-to-creatinine ratio (ACR ≥11.13 mg/g). CKD was defined by an estimated glomerular filtration rate <60 mL/min/1.73 m² or the new presence of albuminuria (ACR ≥30 mg/g).

Results: Overall, 577 (14.7%) participants developed low-grade albuminuria and 164 (4.2%) participants developed CKD during a mean follow-up period of 3.6 years. Compared with participants without metabolic syndrome, those with metabolic syndrome had greater risks of low-grade albuminuria [adjusted odd ratio (OR) and 95% confidence interval (95% CI): 1.30 (1.05–1.61)] and CKD [1.71 (1.20–2.44)]. Moreover, the incidence rates of low-grade albuminuria and CKD increased as the number of metabolic syndrome components increased (P for trend <0.0001).

Conclusions: The presence of metabolic syndrome is associated with increased incidence rates of low-grade albuminuria and CKD the middle-aged and elderly Chinese populations.

Association of daytime napping in relation to risk of diabetes: evidence from a prospective study in Zhejiang, China

BACKGROUND

Diabetes was a major risk factor for numerous chronic diseases. However, the associations between daytime napping and diabetes in the existing literature is still inconsistent.

METHODS

The analysis included 53,916 participants aged 30-79 years of the China Kadoorie Biobank prospective study from Tongxiang. Incident diabetes were identified through linkage with incident diabetes surveillance systems, health insurance system, and death registries. Cox regressions were used to estimate the associations of daytime napping with diabetes.

RESULTS

5.11% of participants reported habitual daytime napping. During 488,233 person-years (median 9.4 years) of follow-up, 3333 incident diabetes, including 1249 males and 2084 females, were documented. After adjusting for socio-demographic status, behavioral lifestyle, BMI, waist circumference and snoring, as comparison with those without daytime napping, the hazard ratios for risk of diabetes were 1.39 (95% CI 1.21-1.59). The corresponding figures for males and females were 1.45 (95% CI 1.20-1.74) and 1.30 (95% CI 1.05-1.59), respectively. The corresponding figures for postmenopausal and premenopausal females were 1.41 (95% CI 1.08-1.80) and 1.13 (95% CI 0.78-1.59), respectively.

CONCLUSIONS

Habitual daytime napping is positively associated with risk of diabetes in adults, except premenopausal females.

Gender and age differences in the association between sleep characteristics and fasting glucose levels in Chinese adults

AIM

The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age.

METHODS

This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models.

RESULTS

Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age.

CONCLUSION

Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

Lipid accumulation product and late-onset hypogonadism in middle-aged and elderly men: results from a cross-sectional study in China

OBJECTIVES

Hypogonadism in men is related to the deterioration of general health. However, the association between lipid overaccumulation and ageing-related hypogonadism remains an undetermined concept. We aimed to provide an insight into the possible links between the lipid accumulation product (LAP) and late-onset hypogonadism (LOH).

SETTING

Sun Yat-sen Memorial Hospital of Sun Yat-sen University.

PARTICIPANTS

We included a population sample of 997 subjects aged 40 years or older.

PRIMARY AND SECONDARY OUTCOME MEASURES

The LAP was calculated by gender-specific equations using waist circumference (WC) and triglyceride (TG). LOH was defined by the presence of androgen deficiency symptoms and low serum total testosterone levels.

RESULTS

The prevalence of LOH was 9.4% in this population and gradually increased according to increasing LAP quartiles. Compared with subjects without LOH, ageing men with LOH had higher body mass index, WC, systolic blood pressure, percentage of subjects currently smoking, TG and follicle stimulating hormone and lower low-density lipoprotein cholesterol and sex hormone binding globulin. In multivariate logistic regression analysis, the adjusted ORs of LOH for increasing LAP quartiles 1-4 were 1.00 (reference), 1.10 (95% CI 0.45-2.69), 2.15 (95% CI 0.93-4.94) and 3.83 (95% CI 1.73-8.45), respectively.

CONCLUSION

Body lipid accumulation evaluated by the LAP is independently associated with the prevalence of LOH in middle-aged and elderly Chinese men.

Parity is associated with albuminuria and chronic kidney disease: a population-based study

Background and aims: Epidemiological studies have shown that increasing parity is associated with risk of hypertension and diabetes in parous women. However, the relationship between the parity degree with chronic kidney disease (CKD) is still unknown.

Results: Parous women with higher parity had increased age, body mass index, waist circumference, systolic blood pressure, fasting plasma glucose, fasting insulin and decreased high-density lipoprotein cholesterol, eGFR and education levels. Compared with women with one-child birth, those with more than two-child births had greater prevalence of increased urinary albumin excretion (odds ratios [ORs] 1.53, 95% confidence intervals [CI], 1.03 - 2.28) and CKD (ORs 1.79, 95% CI, 1.24 - 2.58) after multiple adjustments. In dose-response analysis, a nonlinear relationship of parity degree with albuminuria and CKD was detected.

Conclusion: Parity is associated with higher prevalence of albuminuria and CKD in middle-aged and elderly Chinese women.

Methods: We conducted a community-based study in 6,946 women to investigate the association of parity with albuminuria and CKD. Increased urinary albumin excretion was defined as albumin-to-creatinine ratio (ACR) greater or equal than 30 mg/g. CKD was defined as estimated glomerular filtration rate (eGFR) less than 60 mL/min per 1.73 m² or presence of albuminuria.

Number of parity is associated with low-grade albuminuria in middle-aged and elderly Chinese women

Background

Women with a higher number of pregnancies have a higher risk of developing cardiovascular diseases. Subtle fluctuations in albumin excretion could be related to pathophysiologic changes in the vascular system. We aimed to investigate the possible association of parity with low-grade albuminuria.

Methods

We conducted a community-based study in 6495 women aged 40 years or older. Low-grade albuminuria was defined according to the highest quartile of urine albumin-to-creatinine ratio in participants free of micro- or macro-albuminuria.

Results

Parous women with a higher number of pregnancies had increased age, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), fasting plasma glucose (FPG), and fasting insulin, as well as decreased high-density lipoprotein cholesterol (HDL-C), estimated glomerular filtration rate (eGFR) levels, and proportion of menopause. The prevalence of low-grade albuminuria in parous women gradually increased with parity number. Compared with women with one childbirth, those with more than two childbirths were independently associated with a higher prevalent low-grade albuminuria (odds ratios [ORs] 1.41, 95% confidence interval [CI], 1.09–1.81) after multiple adjustments. In subgroup analysis after multiple adjustments, significant relation between parity number and prevalent low-grade albuminuria was detected in subjects age 55 years or older.

Conclusion

Number of parity is associated with prevalent low-grade albuminuria in middle-aged and elderly Chinese women without micro- or macro-albuminuria.

Association of Daytime Napping and Diagnosed Diabetes in Middle-Aged Premenopausal, Middle-Aged Postmenopausal, and Older Postmenopausal Chinese Women

PURPOSE

To examine associations of daytime napping and diagnosed diabetes in middle-aged premenopausal, middle-aged postmenopausal, and older postmenopausal Chinese women.

DESIGN

Quantitative, cross-sectional.

SETTING

2015 cross-sectional data from China Health and Retirement Longitudinal Study. Participants were recruited from 150 counties/districts and 450 villages/resident committees.

PARTICIPANTS

Six thousand nine hundred and forty women aged 45 years and older (mean age = 61 years) stratified by age and menopausal status.

MEASURES

The outcome was self-reported diagnosed diabetes. The exposure was self-reported daytime napping (0, >0-≤60, or >60 min/d). Participants were stratified to middle-aged premenopausal, middle-aged postmenopausal, and older postmenopausal women according to their age (≤60 or >60 years) and menopausal status.

ANALYSIS

One-way analysis of variance and χ² tests were conducted to explore differences on characteristics of middle-aged premenopausal, middle-aged postmenopausal, and older postmenopausal women. Multiple logistic regressions were used to estimate adjusted odds ratios (ORs) for diagnosed diabetes according to daytime napping in the total sample, middle-aged premenopausal, middle-aged postmenopausal, and older postmenopausal Chinese women.

RESULTS

Participants' mean self-reported daytime napping duration was 34 minutes. Women who napped more than 60 minutes were more likely to report diagnosed diabetes (OR = 1.39, 95% confidence interval (CI), 1.09-1.76) comparing to those who did not nap, after adjusting for potential confounders. No statistical significance of interaction term between daytime napping and age/menopausal status was detected (P = .602 and P = .558) among total women. The stratified analysis revealed the significant association among middle-aged postmenopausal women napping more than 60 minutes (OR = 1.81, 95% CI, 1.18-2.77). The association, however, was found to be insignificant in middle-aged premenopausal women and older postmenopausal women.

CONCLUSIONS

Long daytime nap (>60 min/d) was associated with diagnosed diabetes in middle-aged postmenopausal women in China.

Sleep duration and patterns in Chinese patients with diabetes: A meta-analysis of comparative studies and epidemiological surveys

PURPOSE

A meta-analysis on sleep duration and patterns in patients with diabetes in China.

DESIGN AND METHODS

Two investigators independently carried out a systematic literature search in both international and Chinese databases.

FINDINGS

A total of 47 studies with 98 911 patients were included. The pooled mean sleep duration was 7.15 hours/day in patients with diabetes and 7.49 hours/day in healthy controls. The estimated percentage of short sleep duration of less than 6 hours/day was 23.0% in patients with diabetes and 12.3% in healthy controls, while the proportion of short sleep duration of less than 7 hours/day was 38.0% in patients with diabetes and 14.1% in healthy controls.

PRACTICE IMPLICATIONS

Short sleep duration was common in Chinese patients with diabetes.

Association of daytime napping with incident cardiovascular disease in a community-based population

OBJECTIVE

To investigate the association between self-reported daytime napping habits and cardiovascular disease (CVD) in a large community-based study population.

METHODS

Of the 4170 participants, 55.5% were women and the mean age was 63.1 years (SD, 11.0 years). CVD included cardiovascular death, congestive heart failure, myocardial infarction, stroke, angina, and revascularization and was defined as the first confirmed incidence of CVD during an average 11-year follow-up. Self-reported daytime napping habits were recorded using baseline questionnaires. Backward stepwise Cox regression analysis was used to explore the relationship between CVD and napping habits.

RESULTS

In this study, 914 participants with CVD (21.9%) were observed. Participants who took regular long naps had a higher prevalence of incident CVD than did those who took regular short naps, irregular naps, or no naps (34.5% vs. 28.4%, 22.4%, 16.6%, respectively; P < 0.001). In the final backward stepwise Cox regression model, regular long naps were found to be associated with CVD (HR: 1.403, 95% CI: 1.079-1.825, P = 0.012).

CONCLUSIONS

Regular long daytime napping was an independent risk factor for CVD. Healthy sleep habits may promote human health and prevent CVD.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00005275.

Assessment of adiposity distribution and its association with diabetes and insulin resistance: a population-based study

BACKGROUND

Rational measures in estimating adiposity distribution in diabetic patients has yet to be validated. This study aims to provide insight about the possible links between routinely available body adiposity parameters and the development of both diabetes and insulin resistance.

METHODS

We performed a population-based cross-sectional study in 9496 subjects aged 40 years or older. All of the body adiposity measures including body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), waist-height ratio (WHtR), visceral adiposity index (VAI), body adiposity index (BAI) and lipid accumulation product index (LAP) were separately evaluated according to standard measurement methods. Diabetes was diagnosed according to the American Diabetes Association 2010 criteria.

RESULTS

All tested body adiposity measurements were significantly associated with fasting plasma glucose (FPG), oral glucose tolerance test (OGTT) 2 h glucose, HbA1c and fasting insulin. Compared with other adiposity phenotypes, LAP have shown the relatively strongest while BAI have shown the relatively weakest association with increased odds of both diabetes and insulin resistance across all logistic regression models. Additionally, LAP provided the best discrimination accuracy for diabetes [area under the curve (AUC): 0.658 95% confidence intervals (CI) 0.645-0.671] and insulin resistance (AUC: 0.781 95% CI 0.771-0.792) when compared with other body adiposity parameters.

CONCLUSIONS

The LAP index seems to be a better indicator than other adiposity measures tested in the study to evaluate the association of visceral fat mass with diabetes and insulin resistance, which should be given more consideration in the clinical practice.

Hypoglycaemic activity of 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione in streptozotocin-induced diabetic mice through ameliorating metabolic function and regulating peroxisome proliferator-activated receptor γ

INTRODUCTION

Diabetes mellitus is characterized by hyperglycaemia causing changes in plasma lipoproteins, which leads to insulin resistance, secretion defects or both. The present study aimed to evaluate the ability of 2-dodecyl-6-methoxy-cyclohexa-2,5-diene-1,4-dione (DMDD) isolated from Averrhoa carambola L. roots to lower hyperglycaemia and to investigate its potential mechanism in diabetic mice.

MATERIAL AND METHODS

DMDD was isolated using a column chromatographic technique. Experimental mice were fed with a high-fat diet for a month and were intravenously injected with streptozotocin (80 mg/kg, single dose). Diabetic mice were orally administered DMDD (12.5, 25, 50 mg/kg) and 50 mg/kg pioglitazone for 15 days. Fasting blood glucose (FBG), fasting blood insulin (FINS), pancreatic insulin content, interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), as well as serum total cholesterol (TC), triglyceride (TG) and free fatty acid (FFA) were determined. Adipose tissue was assessed by histological examination, immunohistochemistry, western blot and reverse transcription-polymerase chain reaction methods.

RESULTS

DMDD significantly increased the insulin level (all p < 0.05). In contrast, FBG, IL-6, TNF-α, TC, TG and FFA were significantly decreased (all p < 0.05). However, DMDD induced the activation of adipocyte peroxisome proliferator-activated receptor γ (PPAR-γ), confirmed by increased protein and mRNA expression of PPAR-γ.

CONCLUSIONS

DMDD possessed hypoglycaemic activity due to its potential mechanism involving PPARγ-mediated adipocyte endocrine regulation.

Visceral adiposity index is associated with increased urinary albumin excretion: A population-based study

BACKGROUND

The effects of visceral fat accumulation on the renal damage have drawn much attention. We aimed to investigate the possible relationship between visceral adiposity and albuminuria.

METHODS

We included information from a population-based study in 9473 subjects aged 40 years or older. As a novel and valid indicator for visceral adipose function, visceral adiposity index (VAI) was determined by gender-specific equations and calculated using simple anthropometric and functional parameters. Increased urinary albumin excretion was defined as albumin-to-creatinine ratio (ACR) 30 mg/g or greater.

RESULTS

The prevalence rate of increased urinary albumin excretion was 6.6% in this population and gradually increased across VAI quartiles. Participants with higher VAI had elevated age, blood pressure, cholesterol, fasting insulin and decreased high density lipoprotein cholesterol and estimated glomerular filtration rate (eGFR) level. In multivariate logistic regression analysis, the adjusted odds ratios (ORs) of increased urinary albumin excretion for increasing VAI quartiles were 1.00 (reference), 1.29 (95% confidence intervals [CI] 0.94-1.76), 1.46 (95% CI 1.08-1.97) and 1.79 (95% CI 1.33-2.41). In subgroup analysis and after multiple adjustments, significant relation between VAI level and prevalent increased urinary albumin excretion was detected in women, younger subjects, non-obesity subjects, those without diabetes and those with eGFR ≥60 ml/min per 1.73 m².

CONCLUSION

Visceral fat accumulation evaluating by VAI is independently associated with increased urinary albumin excretion in middle-aged and elderly Chinese.

Gender-specific independent and combined dose-response association of napping and night sleep duration with type 2 diabetes mellitus in rural Chinese adults: the RuralDiab study

OBJECTIVE

The aim of this study was to explore the independent and combined dose-response association of napping and night sleep duration with type 2 diabetes mellitus (T2DM) among different genders in the rural Chinese population.

METHODS

For this research, a total of 19,257 participants were enrolled in the Rural Diabetes, Obesity and Lifestyle (RuralDiab) study. Napping and night sleep duration were assessed using the Pittsburgh Sleep Quality Index (PSQI). Restricted cubic splines and logistic regression were used to estimate the relationship between napping and night sleep duration with T2DM.

RESULTS

A linear dose-response relationship between napping duration and T2DM as well as a U-shaped relationship between night sleep duration and T2DM were found. Compared with those who reported no napping, participants who had a napping duration of ≥91 min were associated with a 19% increase in prevalence of T2DM. Adjusted odds ratios (ORs) (95% confidence intervals (CIs)) for T2DM were 1.48 (1.03, 2.14) and 1.50 (1.22, 1.85) for shorter (≤5 h) and longer (>9 h) night sleep duration compared with the referential group. Additionally, the combination of longer napping duration (≥91 min) and night sleep duration (>9 h) increased 104% (95% CI: 45%, 128%) prevalence for T2DM. These associations were not found in males but were evident in females.

CONCLUSIONS

Longer napping duration and extreme night sleep duration increased the prevalence of T2DM. Meanwhile, longer napping and night sleep duration might be jointly associated with a higher prevalence of T2DM.

Fatty liver index, albuminuria and the association with chronic kidney disease: a population-based study in China

OBJECTIVES

The effects of lipid metabolism disorder on renal damage have drawn much attention. Using the fatty liver index (FLI) as a validated indicator of hepatic steatosis, this study aims to provide insight about the possible links between fatty liver and the development of chronic kidney disease (CKD).

SETTING

Hospital.

PARTICIPANTS

We performed a population-based study on 9436 subjects aged 40 years or older.

PRIMARY AND SECONDARY OUTCOME MEASURES

FLI is calculated using an algorithm based on body mass index, waist circumference, triglycerides and γ-glutamyltransferase. Increased urinary albumin excretion was defined according to the urinary albumin to creatinine ratio ranges ≥30 mg/g. CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² or presence of albuminuria.

RESULTS

There were 620 (6.6%) subjects categorised to have increased urinary albumin excretion and 753 (8.0%) subjects categorised to have CKD. Participants with higher FLI had increased age, blood pressure, low-density lipoprotein cholesterol, fasting plasma glucose, fasting insulin and decreased eGFR level. Prevalence of increased urinary albumin excretion and CKD tended to increase with the elevated FLI quartiles. In logistic regression analysis, compared with subjects in the lowest quartile of FLI, the adjusted ORs in the highest quartile were 2.30 (95% CI 1.36 to 3.90) for increased urinary albumin excretion and 1.93 (95% CI 1.18 to 3.15) for CKD.

CONCLUSION

Hepatic steatosis evaluated by FLI is independently associated with increased urinary albumin excretion and prevalence of CKD in middle-aged and elderly Chinese.