Interaction between sleep duration and trouble sleeping on depressive symptoms among U.S. adults, NHANES 2015-2018

BACKGROUND

This study aims to examine the associations and interaction effects of sleep duration and trouble sleeping on depressive symptoms among U.S. adults.

METHODS

National Health and Nutrition Examination Survey (NHANES) data from 2015 to 2018 were analyzed (N = 10,044). Trouble sleeping and sleep duration were self-reported. Sleep duration was defined as short (≤6 h) or long (≥9 h), compared with normal (>6 and < 9 h). Depressive symptoms were determined by the Patient Health Questionnaire-9 score ≥ 10. Both multiplicative interaction and additive interaction were reported.

RESULTS

There was a significant positive additive interaction between short sleep duration and trouble sleeping on depressive symptoms in the fully adjusted model (Relative excess risk due to interaction, RERIOR = 4.42, 95 % CI: 1.12, 7.73), with 43 % of the association with depressive symptoms attributed to the interaction (attributable proportion of interaction, AP = 0.43, 95 % CI: 0.22, 0.64). Similarly, a significant positive additive interaction between long sleep duration and trouble sleeping on depressive symptoms was found (RERIOR = 4.17, 95 % CI: 0.96, 7.38), with 41 % of the association with depressive symptoms attributed to the interaction (AP = 0.41, 95 % CI: 0.21, 0.60). No multiplicative interaction was detected between short or long sleep duration and trouble sleeping.

LIMITATIONS

The cross-sectional design limits the ability to draw causal inferences.

CONCLUSIONS

Findings suggest that different aspects of sleep health interact synergistically, accounting for a substantial portion of the association with depressive symptoms. This underscores the importance of simultaneously considering multiple dimensions of sleep health in relation to depressive symptoms.

IMPACT OF GENDER ON ASSOCIATION BETWEEN RACE AND DISABILITY: THE CALIFORNIA HEALTH INTERVIEW SURVEY (CHIS)

Women generally have higher prevalence of disability than men in later life. Moreover, Blacks and Hispanics usually have higher prevalence of disability than Whites. Little is known about the impact of gender on the association between race and disability. We used 2015-2016 CHIS data, restricted to adults ≥ 65 years old (n=15,044). Disability was classified as present or absent based on responses on questions related to “to physical, mental, and emotional conditions.” Race was classified as: White, Black, Hispanic, Asian, and Other. We estimated sex- and race-specific proportions and 95% confidence intervals (CI) and used sex-specific multivariable logistic regression to examine the associations between race and disability adjusting for age, education, marital status, cigarette smoking, arthritis, hypertension, and diabetes, mental distress, and walking for work or pleasure. All analyses accounted for complex sampling weights. Approximately 52% of women and 47% of men had disability, while 48% of White, 48% of Black, 60% of Hispanic, 43% of Asian, and 50% of Other race responded as having disability. Adjusting for covariates, Hispanic women had 67% higher odds of having disability compared with White women (OR= 1.67, 95% CI= 1.07–2.60), but there were no differences in male counterparts (OR=1.03, 95% CI=0.68-1.56). Compared with White men, men of Asian or Other race had lower odds for disability, while associations were in the opposite direction in female counterparts; however, associations were not statistically significant. Further research is needed to understand higher prevalence of disability among older minority women compared with White women.

Race and Ethnic Group Differences in Social Engagement Among Older Adults

Social engagement is considered crucial for older adults’ well-being, generating social capital, connecting them to information about healthy lifestyles, and providing coping strategies for addressing daily challenges. Little is known about race and ethnic disparities regarding social engagement. This study examines the relationship between race, Hispanic ethnicity, and social engagement among community-dwelling adults age 65 or older. Data are taken from the Health and Retirement Study (2014) (n=6,221). Race and ethnic status are measured as: non-Hispanic white, non-Hispanic black, non-Hispanic “Asians and other race,” and Hispanic (any race). Social engagement includes frequency of contact with friends and family and participation in social activities (e.g. volunteering and attending religious services). Covariates included age, sex, education, number of co-morbidities, and alcohol consumption. Linear regression analyses were performed using SAS 9.4. The mean age was 74.6, and sixty percent of the sample was female. Race and ethnic distribution were 78.6% non-Hispanic white, 11.9% non-Hispanic black, 7.89% Hispanics, and 1.7% non-Hispanic “Asians and other race.” The mean score for our social engagement index was 3.3 (range 0-6). Hispanic persons, Asian persons, and persons from other race groups had lower social engagement compared with non-Hispanic white persons [β:-0.29, p<.0001; β:-0.27, p=0.04 respectively), after adjusting for covariates. These race and ethnic group differences in social engagement likely contribute to well-document health disparities in later life. Understanding racial and ethnic disparities in social engagement and the factors that create these differences can help identify appropriate social intervention programs regarding improving the well-being of all older adults.

Repeated measurements of serum urate and mortality: a prospective cohort study of 152,358 individuals over 8 years of follow-up

BACKGROUND

Longitudinal evidence on change of serum urate level with mortality risk is limited as prior studies have a measurement of serum urate at a single time point. Further, the combined effect of serum urate and systemic inflammation on mortality is unknown.

METHODS

We conducted a prospective cohort study of 152,358 participants (122,045 men and 30,313 women) with repeated measurements of serum urate in 2006, 2008, 2010, and 2012 (107,751 participants had all four measurements of serum urate). We used the Cox proportional hazard model to examine the association between cumulative average and changes in serum urate with mortality. The combined effect of serum urate and systemic inflammation was determined by testing the interaction of serum urate and high-sensitive C-reactive protein (hs-CRP) in relation to mortality risk.

RESULTS

During a median follow-up of 8.7 (interquartile range 6.3-9.2) years, we identified 7564 all-cause deaths, 1763 CVD deaths, 1706 cancer deaths, and 1572 other deaths. We observed U-shaped relationships of cumulative average serum urate with all-cause mortality, cardiovascular mortality, and other mortalities. Compared with participants with stable serum urate, those with greater increases in serum urate had a 1.7-fold elevated mortality (hazard ratio (HR) = 1.66, 95% confidence interval (CI) = 1.49-1.84), and those with decreased serum urate had a 2-fold elevated mortality risk (HR = 2.14, 95% CI 1.93-2.37). Participants with both hyperuricemia and hs-CRP had 1.6 times higher mortality, compared with those with low serum urate and hs-CRP levels (HR = 1.56, 95% CI 1.37-1.76).

CONCLUSIONS

We observed a U-shaped relationship of long-term cumulative average serum urate with all-cause mortality, cardiovascular mortality, and other mortalities. Compared with participants with relatively stable serum urate levels, a greater increase or decrease in serum urate was associated with elevated mortality. Participants with both hyperuricemia and high systemic inflammation had the greatest mortality risk compared with those with low serum urate and low hs-CRP levels.

Weight Change During the Early Rheumatoid Arthritis Period and Risk of Subsequent Mortality in Women With Rheumatoid Arthritis and Matched Comparators

OBJECTIVE

To investigate whether weight change during the early rheumatoid arthritis (RA) period is associated with subsequent mortality and to evaluate whether there is an RA-specific effect.

METHODS

We identified patients with incident RA during the Nurses' Health Study (NHS; 1976-2016) and created a comparison cohort by matching each RA patient with up to 10 non-RA comparators by age and calendar year of the RA diagnosis (index date). To capture weight change around the early RA period ("peri-RA/index"), we used weight measurements collected 2-4 years before and 2-4 years after the index date. We used Cox regression analysis to estimate hazard ratios (HRs) for mortality according to peri-RA/index weight change categories, separately in each cohort and in the combined cohorts, evaluating for an RA-specific effect.

RESULTS

Among 121,701 women in the NHS, 902 patients with incident RA were identified and matched to 7,884 non-RA comparators. In the RA cohort, 371 deaths (41.1%) occurred during a mean follow-up of 17.0 years after the early RA period, and 2,303 deaths (29.2%) occurred in the comparison cohort during a mean follow-up of 18.4 years. Weight loss of >30 pounds during the peri-RA period had a hazard ratio (HR) for mortality of 2.78 (95% confidence interval [95% CI] 1.58-4.89) compared to stable weight; results in the comparison cohort were similar (HR 2.16, 95% CI 1.61-2.88). A weight gain of >30 pounds had no association with mortality in patients with RA (HR 1.45, 95% CI 0.69-3.07) or comparators (HR 1.19, 95% CI 0.89-1.59). For mortality, there was no statistically significant interaction between RA/comparator status and weight change category (P = 0.68).

CONCLUSION

Severe weight loss during the early RA period was associated with an increased subsequent mortality risk for women with and those without RA. These results extend prior observations by including non-RA comparators and finding no protective association between weight gain and mortality, providing evidence against an RA-specific obesity paradox for mortality.

Optimal vitamin D status and its relationship with bone and mineral metabolism in Hong Kong Chinese

BACKGROUND

Although 25-hydroxyvitamin D (25[OH]D) is commonly used to define vitamin D status, there is no consensus on the cutoff levels for vitamin D deficiency and insufficiency. In this study, we aimed to identify the 25(OH)D threshold that maximally suppressed parathyroid hormone (PTH) in Hong Kong Chinese population.

METHODS

The study included 5276 participants (70% female) of the Hong Kong Osteoporosis Study aged 20 or above who had total 25(OH)D measured. Three-phase segmented regression was used to identify the optimal break-point between 25(OH)D and PTH.

RESULTS

The prevalence of vitamin D deficiency observed was 43.8% and the prevalence of insufficient (<75nmol/L) or deficient (<50nmol/L) vitamin D levels was 90.1% in our study population. Using unadjusted three-phase segmented regression, the estimated first and second break-point of 25(OH)D on PTH suppression were 32nmol/L (95% CI: 29-35) and 89nmol/L (95% CI: 77-101) with an r² of 0.048, whereas the estimated first and second break-point of 25(OH)D were 27nmol/L (95% CI: 24-30) and 47nmol/L (95% CI: 37-56) after adjusting for factors affecting bone and mineral metabolism. In addition, the relationship between 25(OH)D and PTH significantly differed by sex and age.

CONCLUSION

The threshold for 25OHD at the point of maximal suppression of PTH estimated in this study was lower than the suggested threshold of vitamin D deficiency in the literature, perhaps due to race or assay differences, and the relationship between vitamin D and PTH changed with sex and age. Standardization in the methodology of searching for the optimal break-point is desirable so that a consensus on cutoff points can be obtained.

The Association of Vibratory Perception and Muscle Strength With the Incidence and Worsening of Knee Instability: The Multicenter Osteoarthritis Study

OBJECTIVE

To examine neuromuscular factors that predict the incidence and progression of knee instability symptoms in older adults with or at high risk of knee osteoarthritis (OA).

METHODS

At the 60-month clinic visit, participants in the Multicenter Osteoarthritis Study underwent evaluation of quantitative vibratory sense at the knee and isokinetic quadriceps muscle strength. At this 60-month visit, participants were also asked about knee buckling and sensations of knee shifting or slipping without buckling in the past 3 months and then were asked the same questions at the 72- and 84-month follow-up visits. We performed a person-based analysis using Poisson regression analysis with robust error variance to estimate adjusted relative risks (RRs) for the association of vibratory sense and muscle strength with the incidence and worsening of knee slipping/shifting, buckling, and overall knee instability symptoms (either buckling or knee shifting/slipping), with adjustment for relevant confounders.

RESULTS

A total of 1,803 participants (61% women) were included. Approximately one-third of the participants reported incident or worsening of instability symptoms over the study period. After adjustment for relevant confounders, better vibratory acuity (adjusted RR 0.78, 95% confidence interval [95% CI] 0.56-1.09), P = 0.020 for trend) and greater quadriceps strength (adjusted RR 0.53, 95% CI 0.38-0.75, P < 0.001) protected against incident knee instability symptoms. Greater quadriceps strength (adjusted RR 0.73, 95% CI 0.58-0.92, P = 0.008) also protected against worsening of knee instability symptoms.

CONCLUSION

Vibratory acuity and quadriceps muscle strength are important predictors of the incidence and worsening of knee instability over 2 years. These neuromuscular factors are potentially modifiable and should be considered in interventional studies of instability in persons with or at risk of knee OA.

Selection bias in rheumatic disease research

The identification of modifiable risk factors for the development of rheumatic conditions and their sequelae is crucial for reducing the substantial worldwide burden of these diseases. However, the validity of such research can be threatened by sources of bias, including confounding, measurement and selection biases. In this Review, we discuss potentially major issues of selection bias--a type of bias frequently overshadowed by other bias and feasibility issues, despite being equally or more problematic--in key areas of rheumatic disease research. We present index event bias (a type of selection bias) as one of the potentially unifying reasons behind some unexpected findings, such as the 'risk factor paradox'--a phenomenon exemplified by the discrepant effects of certain risk factors on the development versus the progression of osteoarthritis (OA) or rheumatoid arthritis (RA). We also discuss potential selection biases owing to differential loss to follow-up in RA and OA research, as well as those due to the depletion of susceptibles (prevalent user bias) and immortal time bias. The lesson remains that selection bias can be ubiquitous and, therefore, has the potential to lead the field astray. Thus, we conclude with suggestions to help investigators avoid such issues and limit the impact on future rheumatology research.

The impact of ethnicity, family income, and parental education on children's health and use of health services

OBJECTIVES

This study characterized ethnic disparities for children in demographics, health status, and use of services; explored whether ethnic subgroups (Puerto Rican, Cuban, and Mexican) have additional distinctive differences; and determined whether disparities are explained by differences in family income and parental education.

METHODS

Bivariate and multivariate analyses of data on 99,268 children from the 1989-91 National Health Interview Surveys were conducted.

RESULTS

Native American, Black, and Hispanic children are poorest (35%, 41% below poverty level vs 10% of Whites), least healthy (66%-74% in excellent or very good health vs 85% of Whites), and have the least well educated parents. Compared with Whites, non-White children average fewer doctor visits and are more likely to have excessive intervals between visits. Hispanic subgroup differences in demographics, health, and use of services equal or surpass differences among major ethnic groups. In multivariate analyses, almost all ethnic group disparities persisted after adjustment for family income, parental education, and other relevant covariates.

CONCLUSIONS

Major ethnic groups and subgroups of children differ strikingly in demographics, health, and use of services; subgroup differences are easily overlooked; and most disparities persist even after adjustment for family income and parental education.

Effect of response to a low-fat diet among adolescent males on their adult blood cholesterol levels

BACKGROUND

While primary prevention of adult cardiovascular diseases should begin early, there are problems in identifying children at increased risk of future disease.

METHODS

We did a follow-up study in 1991-1992 of 100 male former students at a boarding high school who had blood cholesterol measured in 1970-1971 both prior to and following a school-wide, reduced-fat dietary intervention. We compared adult cholesterol levels of the 50 subjects whose cholesterol decreased > or = 16.5% (the median decrease) following the 1970-1971 intervention (Diet-Sensitive) with the 50 whose response was < 16.5% (Non-Diet-Sensitive).

RESULTS

Blood cholesterol of adults who were Diet-Sensitive in 1970-1971 was 4.2 mg/dl lower than their baseline values in adolescence, while adults classified as Non-Diet-Sensitive as adolescents showed a 15.9 mg/ dl increase in cholesterol over 21 years. Adjusting for baseline adolescent values, Non-Diet-Sensitive subjects were 4.8 (95% CI 1.4, 15.9) times as likely as Diet-Sensitive subjects to have adult cholesterol > or = 200 mg/ dl. Also, Diet-Sensitive adults on a low-fat diet had adult blood cholesterol levels > 20 mg/dl lower than Non-Diet-Sensitive adults on a similar diet (180.1 vs 202.1 mg/dl, respectively).

CONCLUSIONS

Degree of response to a low-fat, low-cholesterol diet during adolescence may identify male subjects who will have differing patterns of cholesterol change over time.

Risk profiles for non-communicable diseases in rural and urban schoolchildren in the Republic of Cameroon

OBJECTIVES

In developing countries, there is evidence that the median age of the population and the life expectancy at birth are increasing as a result of decreasing fertility rates and infant mortality. The result is an aging population more prone to non-communicable diseases such as diabetes, cancer, or heart disease later in life. In addition, changing lifestyle factors such as tobacco use, physical inactivity, and high fat diets, may accelerate the emergence of such chronic diseases as major causes of death and disability in these countries, particularly in urban areas. To test the premise that urban living predisposes residents to reduced activity levels, less healthy diets, cigarette smoking, elevated blood pressure, and increased body fat early in life, we studied rural/urban differences in these risk factors among schoolchildren in the Republic of Cameroon.

METHODS

One hundred and nineteen Class 7 schoolchildren (50 urban and 69 rural) were interviewed concerning diet, physical activity, smoking, and alcohol use; blood pressure and anthropometric measurements were also taken.

RESULTS

Physical activity among rural children was more than twice that of urban children, and most of the activity for rural children was work-related. Rural children consumed fewer foods containing fat and more fruits and vegetables. Adjusting for age, systolic and diastolic blood pressures of urban boys were higher than those of rural boys, and among urban children there was a trend toward a larger age-adjusted mean body mass index (BMI). There were no differences in alcohol or tobacco use between urban and rural children.

CONCLUSIONS

In this study, urbanization was associated with a less active lifestyle and a dietary pattern that was higher in fat and lower in fruit and vegetable intake. Since risk factors for non-communicable diseases tend to appear early in life and track into adulthood, it is important to identify those children, or groups of children, with unfavorable risk profiles and to structure health education and promotion programs to modify these trends.

Teratogenicity of high vitamin A intake

BACKGROUND

Studies in animals indicate that natural forms of vitamin A are teratogenic. Synthetic retinoids chemically similar to vitamin A cause birth defects in humans; as in animals, the defects appear to affect tissues derived from the cranial neural crest.

METHODS

Between October 1984 and June 1987, we identified 22,748 pregnant women when they underwent screening either by measurement of maternal serum alpha-fetoprotein or by amniocentesis. Nurse interviewers obtained information on the women's diet, medications, and illnesses during the first trimester of pregnancy, as well as information on their family and medical history and exposure to environmental agents. We obtained information on the outcomes of pregnancy from the obstetricians who delivered the babies or from the women themselves. Of the 22,748 women, 339 had babies with birth defects; 121 of these babies had defects occurring in sites that originated in the cranial neural crest.

RESULTS

For defects associated with cranial-neural-crest tissue, the ratio of the prevalence among the babies born to women who consumed more than 15,000 IU of preformed vitamin A per day from food and supplements to the prevalence among the babies whose mothers consumed 5000 IU or less per day was 3.5 (95 percent confidence interval, 1.7 to 7.3). For vitamin A from supplements alone, the ratio of the prevalence among the babies born to women who consumed more than 10,000 IU per day to that among the babies whose mothers consumed 5000 IU or less per day was 4.8 (95 percent confidence interval, 2.2 to 10.5). Using a smoothed regression curve, we found an apparent threshold near 10,000 IU per day of supplemental vitamin A. The increased frequency of defects was concentrated among the babies born to women who had consumed high levels of vitamin A before the seventh week of gestation.

CONCLUSIONS

High dietary intake of preformed vitamin A appears to be teratogenic. Among the babies born to women who took more than 10,000 IU of preformed vitamin A per day in the form of supplements, we estimate that about 1 infant in 57 had a malformation attributable to the supplement.

Preschool physical activity level and change in body fatness in young children. The Framingham Children's Study

This study examined the effect of preschool physical activity on the change in body fatness from preschool to first grade. The Framingham Children's Study, a longitudinal study of childhood cardiovascular risk behaviors, began in 1987 with the enrollment of 106 children aged 3-5 years and their parents. The present analyses include 97 healthy children with complete data from study entry into first grade. Physical activity was assessed twice yearly for 5 days with an electronic motion sensor. The authors estimated change in the child's level of body fat from preschool to first grade by using the slopes of triceps and subscapular skinfolds and body mass index. On average, active girls (i.e., those with above-median activity levels) gained 1.0 mm in their triceps skinfolds from baseline to first grade, while inactive girls gained 1.75 mm. Active boys lost an average of 0.75 mm in their triceps, while inactive boys gained 0.25 mm. When age, television viewing, energy intake, baseline triceps, and parents' body mass indices were controlled for, inactive preschoolers were 3.8 (95% confidence interval 1.4-10.6) times as likely as active preschoolers to have an increasing triceps slope during follow up (rather than a stable or decreasing slope). This relative risk estimate was slightly higher for children with more body fat at baseline. In this study, preschool-aged children with low levels of physical activity gained substantially more subcutaneous fat than did more active children.

Effect of calcium supplementation on blood pressure in children

OBJECTIVE

To evaluate the effect of calcium supplementation on blood pressure in children.

DESIGN

Randomized, double-masked, placebo-controlled trial.

SETTING AND PARTICIPANTS

One hundred one fifth-grade students in one inner-city school.

INTERVENTION

Each child consumed 480 ml of juice beverages, containing either no calcium or 600 mg calcium (as calcium citrate malate) daily for 12 weeks.

MEASUREMENTS

At baseline we obtained nutrient data from three sets of 2-day food records on each subject. We measured blood pressure four times on each of three weekly sittings at baseline and at follow-up. Using multiple linear regression analysis, we compared mean blood pressure change in the intervention group with that in the placebo group.

RESULTS

There were 50 girls and 51 boys; 61 subjects were black. At baseline, mean age was 11.0 years, systolic and diastolic blood pressures were 101.7 and 57.7 mm Hg, daily total energy intake was 1966 kcal, and calcium intake was 827 mg. With control for age, height, hours of television watched, and baseline blood pressure, systolic blood pressure increased 1.0 mm Hg in the intervention group and 2.8 mm Hg in the placebo group (effect estimate = -1.8 mm Hg; 95% confidence interval -4.0, 0.3). In black subjects the intervention effect estimate was -2.0 mm Hg (95% confidence interval -4.4, 0.4). From lowest to highest quartile of baseline calcium intake (per 1000 kcal), the intervention effect estimates were -3.5, -2.8, -1.3, and 0.0 mm Hg (p for trend = 0.009). There was little effect on diastolic blood pressure.

CONCLUSION

These data suggest a blood pressure-lowering effect of calcium supplementation in children, especially in subjects with low baseline calcium intake.