Thirumagal Kanagasabai

Contribution of Inflammation, Oxidative Stress, and Antioxidants to the Relationship between Sleep Duration and Cardiometabolic Health.

OBJECTIVES To explore the interrelationship and mediating effect of factors that are beneficial (i.e., antioxidants) and harmful (i.e., inflammation and oxidative stress) to the relationship between sleep and cardiometabolic health. DESIGN Cross-sectional data from the 2005-2006 National Health and Nutrition Examination Survey. SETTING Nationally representative population sample from the US. PARTICIPANTS Age ≥ 20 y with sleep data; final analytical sample of n = 2,079. INTERVENTIONS N/A. MEASUREMENTS AND RESULTS Metabolic syndrome was classified according to the Joint Interim Statement, and sleep duration was categorized as very short, short, adequate, and long sleepers (≤ 4, 5-6, 7-8, and ≥ 9 h per night, respectively). The indirect mediation effect was quantified as large (≥ 0.25), moderate (≥ 0.09), modest (≥ 0.01), and weak (< 0.01). In general, inflammation was above the current clinical reference range across all sleep duration categories, whereas oxidative stress was elevated among short and very short sleepers. Select sleep duration- cardiometabolic health relationships were mediated by C-reactive protein (CRP), γ-glutamyl transferase (GGT), carotenoids, uric acid, and vitamins C and D, and were moderated by sex. Specifically, moderate-to-large indirect mediation by GGT, carotenoids, uric acid, and vitamin D were found for sleep duration-waist circumference and -systolic blood pressure relationships, whereas vitamin C was a moderate mediator of the sleep duration-diastolic blood pressure relationship. CONCLUSIONS Several factors related to inflammation, oxidative stress, and antioxidant status were found to lie on the casual pathway of the sleep duration-cardiometabolic health relationship. Further longitudinal studies are needed to confirm our results.

Inflammation, Oxidative Stress, and Antioxidants Contribute to Selected Sleep Quality and Cardiometabolic Health Relationships: A Cross-Sectional Study.

Sleep is vital for cardiometabolic health, but a societal shift toward poor sleep is a prominent feature of many modern cultures. Concurrently, factors such as diet and lifestyle have also changed and may mediate the relationship between sleep quality and cardiometabolic health. Objectives were to explore (1) the interrelationship and (2) mediating effect of inflammation, oxidative stress, and antioxidants on sleep quality and cardiometabolic health. Cross-sectional data from the US National Health and Nutritional Examination Survey 2005-06 (≥20 y; N = 2,072) was used. Cardiometabolic health was defined as per the Joint Interim Statement; overall sleep quality was determined from six sleep habits and categorized as good, fair, poor, and very poor. Fair quality sleepers had optimal inflammation, oxidative stress, and antioxidant levels. Inflammation was above the current clinical reference range across all sleep quality categories, while oxidative stress was only within the clinical reference range for fair sleep quality. Selected sleep quality-cardiometabolic health relationships were mediated by inflammation, oxidative stress, and antioxidants and were moderated by sex. Our results provide initial evidence of a potential role for inflammation, oxidative stress, and antioxidants in the pathway between poor sleep quality-cardiometabolic decline. Further prospective research is needed to confirm our results.

Metabolic Syndrome and Prevalent Any-site, Prostate, Breast and ColonCancers in the U.S. Adult Population: NHANES 1999-2010

Background: Metabolic Syndrome (MetS) is associated with elevated risk of diabetes, cardiovascular disease, and premature mortality. To date, however, the association between MetS and obesity-related cancers has not been systematically assessed within a population-based sample. Methods: In order to quantify the association between MetS and its components on any-site, breast, prostate, and colon cancers, data from the U.S. NHANES 1999-2010 (n=15 141, 18-85 years) were used. Results: In general, the prevalence of MetS was higher amongst those with a self-reported history of cancer. Although MetS, its individual components, and total number of components were positively related to odds of any-site, breast, prostate, and colon cancers, this effect was almost entirely eliminated after adjustment for age. In age-adjusted models, elevated blood glucose was associated with higher odds of prostate (OR: 1.67, 95% CI: 1.08-2.56) and colon cancer (OR: 1.60, 95% CI: 1.02-2.53), and a protective effect of low HDL cholesterol on prostate cancer (OR: 0.64, 95% CI: 0.43-0.94). Further adjustment for sex, ethnicity, income, education, smoking, alcohol, and recreational/ leisure-time physical activity had only minimal influence on these associations. In multivariable analyses, no uniform linear trends were observed between the number of MetS components and site-specific cancers. Conclusion: After accounting for covariates, no consistent association between MetS and any-site, breast, prostate, or colon cancer was observed. Further prospective study is necessary to confirm and extend our understanding of the role of age and other risk factors on the inter-relationship between metabolic health and cancer.

Sleep duration and the associated cardiometabolic risk scores in adults

Objectives: To identify the sleep duration associated with the lowest cardiometabolic risk score in adults and to determine if the association varies by subgroups (eg, sex, age groups, ethnicity, and smoking status). Design: Cross‐sectional data from the 2005–2012 National Health and Nutrition Examination Survey. Setting: Non‐institutionalized civil sample from the United States. Participants: Age ≥20 y (N = 8827) with sleep and cardiometabolic health data. Interventions: N/A. Measurements: Sleep duration from the Sleep Disorders Questionnaire was categorized as ≤3, 4, 5, 6, 7, 8, 9, and ≥10 h per night. HDL cholesterol (HDL) and waist circumference (WC) were stratified by sex first, while fasting insulin, fasting plasma glucose (Glu), triglycerides (TG), body max index (BMI), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were standardized without stratifications. The standardized scores were summed for each participant using the following formula: −zHDL + zInsulin + zGlu + zTG + (zBMI + zWC)/2 + (zSBP + zDBP)/2. Results: Seven hours of sleep was associated with the lowest cardiometabolic risk score (−0.30 (95% CI: −0.43, −0.18)), which remained similar after adjusting for age, sex, ethnicity, education, family income, alcohol intake and smoking status. However, 8 hours of sleep was associated with the lowest score in non‐Hispanic Blacks. Conclusions: This study supports recent sleep duration recommendations in adults, and provides evidence that in general 7 hours of sleep per night is associated with optimal cardiometabolic health of adults. Longitudinal studies using objective measures of sleep would help further clarify this association.

Associations between Sleep Habits and Dysglycemia in US Adults: A Cross-sectional Analysis

OBJECTIVES To examine the independent and joint associations between sleep duration and quality with glycated hemoglobin (A1C) levels and dysglycemia in non-institutionalized adults living in the United States. METHODS Data from the United States National Health and Nutrition Examination Survey (2005-2008) were used (N=9478; ≥20 years). Information on sleep quantity and quality were derived from the Sleep Disorders Questionnaire and used to classify sleep quality as good, fair, poor, or very poor. RESULTS Overall, sleep quantity and quality were related to A1C levels in our unadjusted models. In general, a U-shaped relationship between sleep quantity and A1C levels was observed. Compared to those who slept for 7 to 8 hours per night, sleeping for 4 hours or fewer was associated with higher A1C levels (mean, 95% CI; 5.49%, 5.45 to 5.53 vs. 5.69%, 5.60 to 5.77; p<0.05), whereas only those reporting good and very poor sleep quality had higher A1C levels than poor sleepers (mean, 95% CI: 5.63%, 5.57 to 5.69; 5.56%, 5.52 to 5.60 vs. 5.46%, 5.42 to 5.50; p<0.05). The relationships among sleep duration and quality and the joint effects of sleep quality and quantity and dysglycemia were not significant after multivariable adjustment. CONCLUSIONS Between 7 and 8 hours of sleep and fair/poor sleep quality were associated with optimal A1C levels, while sleeping for fewer or more hours appeared to increase dysglycemia, without adjustment for covariates. These relationships were attenuated following multivariable adjustment. Future research is necessary to refine our understanding of the sleep/glycemic-control relationship to provide a context for the clinical significance of these findings for longer-term A1C control in adults with diabetes.

Associations Between Sleep Habits and Dysglycemia in Adults in the United States: A Cross-Sectional Analysis

OBJECTIVES To examine the independent and joint associations between sleep duration and quality with glycated hemoglobin (A1C) levels and dysglycemia in non-institutionalized adults living in the United States. METHODS Data from the United States National Health and Nutrition Examination Survey (2005-2008) were used (N=9478; ≥20 years). Information on sleep quantity and quality were derived from the Sleep Disorders Questionnaire and used to classify sleep quality as good, fair, poor, or very poor. RESULTS Overall, sleep quantity and quality were related to A1C levels in our unadjusted models. In general, a U-shaped relationship between sleep quantity and A1C levels was observed. Compared to those who slept for 7 to 8 hours per night, sleeping for 4 hours or fewer was associated with higher A1C levels (mean, 95% CI; 5.49%, 5.45 to 5.53 vs. 5.69%, 5.60 to 5.77; p<0.05), whereas only those reporting good and very poor sleep quality had higher A1C levels than poor sleepers (mean, 95% CI: 5.63%, 5.57 to 5.69; 5.56%, 5.52 to 5.60 vs. 5.46%, 5.42 to 5.50; p<0.05). The relationships among sleep duration and quality and the joint effects of sleep quality and quantity and dysglycemia were not significant after multivariable adjustment. CONCLUSIONS Between 7 and 8 hours of sleep and fair/poor sleep quality were associated with optimal A1C levels, while sleeping for fewer or more hours appeared to increase dysglycemia, without adjustment for covariates. These relationships were attenuated following multivariable adjustment. Future research is necessary to refine our understanding of the sleep/glycemic-control relationship to provide a context for the clinical significance of these findings for longer-term A1C control in adults with diabetes.

Association between Sleep Habits and Metabolically Healthy Obesity in Adults: A Cross-Sectional Study

Higher body mass index (BMI) increases the risk of cardiometabolic diseases, but nearly a third of the people living with obesity (BMI: ≥30 kg/m2) are metabolically healthy (MHO). Extreme sleep durations and poor sleep quality are associated with higher bodyweight and cardiometabolic dysfunction, but the full extent to which sleep habits may help differentiate those with MHO versus metabolically abnormal obesity (MAO) is not yet known. Data from the U.S. National Health and Nutritional Examination Survey 2005–08 was used (BMI: ≥30 kg/m2; ≥20 y; N = 1,777). The absence of metabolic syndrome was used to define MHO. Those with MHO tended to be younger, female, Non-Hispanic Black, never smokers, more physically active, and with less physician diagnosed sleep disorders than MAO. Neither sleep duration nor overall sleep quality was related to MHO in crude or multivariable adjusted analyses; however, reporting “almost always” to having trouble falling asleep (OR (95% CI): 0.40 (0.20–0.78)), waking up during the night (0.38 (0.17–0.85)), feeling unrested during the day (0.35 (0.18–0.70)), and feeling overly sleepy during the day (0.35 (0.17–0.75)) was related to lower odds of MHO. Selected sleep quality factors, but not sleep quantity or overall sleep quality, are associated with the MHO phenotype.

Original ResearchAssociations between Sleep Habits and Dysglycemia in US Adults: A Cross-sectional Analysis

OBJECTIVES To examine the independent and joint associations between sleep duration and quality with glycated hemoglobin (A1C) levels and dysglycemia in non-institutionalized adults living in the United States. METHODS Data from the United States National Health and Nutrition Examination Survey (2005-2008) were used (N=9478; ≥20 years). Information on sleep quantity and quality were derived from the Sleep Disorders Questionnaire and used to classify sleep quality as good, fair, poor, or very poor. RESULTS Overall, sleep quantity and quality were related to A1C levels in our unadjusted models. In general, a U-shaped relationship between sleep quantity and A1C levels was observed. Compared to those who slept for 7 to 8 hours per night, sleeping for 4 hours or fewer was associated with higher A1C levels (mean, 95% CI; 5.49%, 5.45 to 5.53 vs. 5.69%, 5.60 to 5.77; p<0.05), whereas only those reporting good and very poor sleep quality had higher A1C levels than poor sleepers (mean, 95% CI: 5.63%, 5.57 to 5.69; 5.56%, 5.52 to 5.60 vs. 5.46%, 5.42 to 5.50; p<0.05). The relationships among sleep duration and quality and the joint effects of sleep quality and quantity and dysglycemia were not significant after multivariable adjustment. CONCLUSIONS Between 7 and 8 hours of sleep and fair/poor sleep quality were associated with optimal A1C levels, while sleeping for fewer or more hours appeared to increase dysglycemia, without adjustment for covariates. These relationships were attenuated following multivariable adjustment. Future research is necessary to refine our understanding of the sleep/glycemic-control relationship to provide a context for the clinical significance of these findings for longer-term A1C control in adults with diabetes.