Summary
The risk of type 2 diabetes among obese adults who are metabolically healthy has not been established. We systematically searched Medline (1946–August 2013) and Embase (1947–August 2013) for ...prospective studies of type 2 diabetes incidence (defined by blood glucose levels or self‐report) among metabolically healthy obese adults (defined by body mass index BMI and normal cardiometabolic clustering, insulin profile or risk score) aged ≥18 years at baseline. We supplemented the analysis with an original effect estimate from the English Longitudinal Study of Ageing (ELSA), with metabolically healthy obesity defined as BMI ≥ 30 kg m−2 and <2 of hypertension, impaired glycaemic control, systemic inflammation, adverse high‐density lipoprotein cholesterol and adverse triglycerides. Estimates from seven published studies and ELSA were pooled using random effects meta‐analyses (1,770 healthy obese participants; 98 type 2 diabetes cases). The pooled adjusted relative risk (RR) for incident type 2 diabetes was 4.03 (95% confidence interval = 2.66–6.09) in healthy obese adults and 8.93 (6.86–11.62) in unhealthy obese compared with healthy normal‐weight adults. Although there was between‐study heterogeneity in the size of effects (I2 = 49.8%; P = 0.03), RR for healthy obesity exceeded one in every study, indicating a consistently increased risk across study populations. Metabolically healthy obese adults show a substantially increased risk of developing type 2 diabetes compared with metabolically healthy normal‐weight adults. Prospective evidence does not indicate that healthy obesity is a harmless condition.
Although it has been hypothesized that the depression-obesity relation is bidirectional, few studies have addressed this hypothesis in a prospective setting. We aimed to examine the bidirectional ...relationship in middle-aged and elderly women.
A total of 65 955 women aged 54-79 years in the Nurses' Health Study were prospectively followed from 1996 to 2006 with updated information on body weight, depression status and various covariates every 2 years. Depression was defined as self-report of physician-diagnosed depression and/or antidepressant use. Obesity was defined as a BMI ≥30.0 kg m(-2). The first three waves (1996-2000) were used as the baseline period and the last three waves (2002-2006) were used as the follow-up period.
After adjusting for baseline age, physical activity, comorbidities, BMI and other covariates, depression at the baseline period was associated with an increased risk of obesity at the follow-up period in all women (multivariate-adjusted odds ratio (OR), 1.38; 95% confidence interval (95% CI), 1.24-1.53) and baseline non-obese women (OR, 1.51; 95% CI, 1.36-1.67). In the opposite direction, after adjusting for baseline age, physical activity, comorbidities, depression status and other covariates, obese women at baseline had a moderately increased risk of depression at the follow-up period compared with normal-weight women (OR, 1.11; 95% CI, 1.03-1.18), and this association was similar for new onset of depression (OR for obese versus normal weight women, 1.10; 95% CI, 1.02-1.20).
Our results suggest a bidirectional association between depression and obesity in middle-aged and elderly women. Future studies are needed to confirm our findings in different populations, and investigate the potential mechanisms underlying this association. Our results underscore the importance of early detection and proper behavioral modifications to lower the burden of both conditions.
We examined the role of sarcopenic obesity as a risk factor for new-onset depressive symptoms over 6-year follow-up in a large sample of older adults.
The sample comprised 3862 community dwelling ...participants (1779 men, 2083 women; mean age 64.6±8.3 years) without depressive symptoms at baseline, recruited from the English Longitudinal Study of Ageing. At baseline and 4-year follow-up, handgrip strength (kg) of the dominant hand was assessed using a hand-held dynamometer, as a measure of sarcopenia. The outcome was new onset depressive symptoms at 6-year follow-up, defined as a score of ⩾4 on the 8-item Centre of Epidemiological Studies Depression scale. Sarcopenic obesity was defined as obese individuals (body mass index ⩾30 kg m(-)(2)) in the lowest tertile of sex-specific grip strength (<35.3 kg men; <19.6 kg women).
Using a multivariable logistic regression model, the risk of depressive symptoms was greatest in obese adults in the lowest tertile of handgrip strength (odds ratio (OR), 1.79, 95% confidence interval (CI), 1.10, 2.89) compared with non-obese individuals with high handgrip strength. Participants who were obese at baseline and had a decrease of more than 1 s.d. in grip strength over 4-year follow-up were at greatest risk of depressive symptoms (OR=1.97, 95% CI, 1.22, 3.17) compared with non-obese with stable grip strength.
A reduction in grip strength was associated with higher risk of depressive symptoms in obese participants only, suggesting that sarcopenic obesity is a risk factor for depressive symptoms.
Objectif Le phénotype « obèses métaboliquement sains » désigne les sujets obèses ayant un profil métabolique favorable. Nous avons examiné l’association entre ce phénotype et la survenue d’un diabète ...de type 2 (DT2) d’une part, et d’un événement cardiovasculaire (ECV) d’autre part. Matériels et méthodes L’indice de masse corporelle (IMC) et le statut métabolique défini en utilisant le critère de l’ATP-III ont été mesurés chez 7 122 participants (69,7 % d’hommes) de la cohorte Whitehall II, entre 1991 et 1993. En croisant l’IMC (poids normal, surpoids, obésité) et le statut métabolique (sain/ anormal), six groupes ont été créés. Leur association avec la survenue d’un DT2 ou d’un ECV incident, chez des sujets indemnes à l’inclusion a été mesurée jusqu’en 2009 et analysée par des modèles de Cox (HR, IC 95 %). Résultats Au total, 657 participants (9,2 %) étaient obèses et parmi eux 42,5 % étaient métaboliquement sains. Durant le suivi, 828 cas d’ECV et 798 DT2 ont été dénombrés. En comparaison aux individus métaboliquement sains de poids normal, les obèses métaboliquement sains avaient un risque élevé d’ECV: 1,97 (1,38–2,80) et de DT2 : 3,25 (2,32–4,54). En comparant les sujets obèses avec anomalies métaboliques aux sujets obèses métaboliquement sains, seul le risque de DT2 était augmenté : 1,98 (1,39–2,83). Conclusion Pour les événements de santé tels que le DT2, le phénotype obèse métaboliquement sain est associé à un risque moindre comparé aux obèses avec anomalies métaboliques. En revanche, aucune différence n’était observée entre les deux groupes pour la survenue d’un événement cardiovasculaire après 17 ans de suivi.
The hypothesis of metabolically healthy obesity posits that adverse health effects of obesity are largely avoided when obesity is accompanied by a favorable metabolic profile. We tested this ...hypothesis with depressive symptoms as the outcome using cross-sectional data on obesity, metabolic health and depressive symptoms. Data were extracted from eight studies and pooled for individual-participant meta-analysis with 30,337 men and women aged 15-105 years (mean age=46.1). Clinic measures included height, weight and metabolic risk factors (high blood pressure, high triglycerides, low high-density lipoprotein cholesterol, high C-reactive protein and high glycated hemoglobin). Depressive symptoms were assessed using clinical interview or standardized rating scales. The pooled sample comprised 7673 (25%) obese participants (body mass index ⩾30 kg m(-2)). Compared to all non-obese individuals, the OR for depressive symptoms was higher in metabolically unhealthy obese individuals with two or more metabolic risk factors (1.45; 95% confidence interval (CI)=1.30, 1.61) and for metabolically healthy obese with ⩽1 metabolic risk factor (1.19; 95% CI=1.03, 1.37), adjusted for sex, age and race/ethnicity. Metabolically unhealthy obesity was associated with higher depression risk (OR=1.23; 95% CI=1.05, 1.45) compared with metabolically healthy obesity. These associations were consistent across studies with no evidence for heterogeneity in estimates (all I(2)-values<4%). In conclusion, obese persons with a favorable metabolic profile have a slightly increased risk of depressive symptoms compared with non-obese, but the risk is greater when obesity is combined with an adverse metabolic profile. These findings suggest that metabolically healthy obesity is not a completely benign condition in relation to depression risk.
The correlation between objective and self-reported measures of physical activity varies between studies. We examined this association and whether it differed by demographic factors or socioeconomic ...status (SES). Data were from 3,975 Whitehall II (United Kingdom, 2012-2013) participants aged 60-83 years, who completed a physical activity questionnaire and wore an accelerometer on their wrist for 9 days. There was a moderate correlation between questionnaire- and accelerometer-assessed physical activity (Spearman's r = 0.33, 95% confidence interval: 0.30, 0.36). The correlations were higher in high-SES groups than in low-SES groups (P 's = 0.02), as defined by education (r = 0.38 vs. r = 0.30) or occupational position (r = 0.37 vs. r = 0.29), but did not differ by age, sex, or marital status. Of the self-reported physical activity, 68.3% came from mild activities, 25% from moderate activities, and only 6.7% from vigorous activities, but their correlations with accelerometer-assessed total physical activity were comparable (range of r 's, 0.21-0.25). Self-reported physical activity from more energetic activities was more strongly associated with accelerometer data (for sports, r = 0.22; for gardening, r = 0.16; for housework, r = 0.09). High-SES persons reported more energetic activities, producing stronger accelerometer associations in these groups. Future studies should identify the aspects of physical activity that are most critical for health; this involves better understanding of the instruments being used.
Objective To quantify the link between lower, subclinically symptomatic, levels of psychological distress and cause-specific mortality in a large scale, population based study. Design Individual ...participant meta-analysis of 10 large prospective cohort studies from the Health Survey for England. Baseline psychological distress measured by the 12 item General Health Questionnaire score, and mortality from death certification.Participants 68 222 people from general population samples of adults aged 35 years and over, free of cardiovascular disease and cancer, and living in private households in England at study baseline.Main outcome measures Death from all causes (n=8365), cardiovascular disease including cerebrovascular disease (n=3382), all cancers (n=2552), and deaths from external causes (n=386). Mean follow-up was 8.2 years (standard deviation 3.5).Results We found a dose-response association between psychological distress across the full range of severity and an increased risk of mortality (age and sex adjusted hazard ratio for General Health Questionnaire scores of 1-3 v score 0: 1.20, 95% confidence interval 1.13 to 1.27; scores 4-6: 1.43, 1.31 to 1.56; and scores 7-12: 1.94, 1.66 to 2.26; P<0.001 for trend). This association remained after adjustment for somatic comorbidity plus behavioural and socioeconomic factors. A similar association was found for cardiovascular disease deaths and deaths from external causes. Cancer death was only associated with psychological distress at higher levels.Conclusions Psychological distress is associated with increased risk of mortality from several major causes in a dose-response pattern. Risk of mortality was raised even at lower levels of distress.
There is some evidence to suggest that obesity is a risk factor for the development of depression, although this is not a universal finding. This discordance might be ascribed to the existence of a ...'healthy obese phenotype'--that is, obesity in the absence of the associated burden of cardiometabolic risk factors. We examined whether the association of obesity with depressive symptoms is dependent on the individual's metabolic health. Participants were 3851 men and women (aged 63.0±8.9 years, 45.1% men) from the English Longitudinal Study of Ageing, a prospective study of community dwelling older adults. Obesity was defined as body mass index ≥30 kg m(-2). Based on blood pressure, high-density lipoprotein cholesterol, triglycerides, glycated haemoglobin and C-reactive protein, participants were classified as 'metabolically healthy' (0 or 1 metabolic abnormality) or 'unhealthy' (≥2 metabolic abnormalities). Depressive symptoms were assessed at baseline and at 2 years follow-up using the 8-item Centre of Epidemiological Studies Depression (CES-D) scale. Obesity prevalence was 27.5%, but 34.3% of this group was categorized as metabolically healthy at baseline. Relative to non-obese healthy participants, after adjustment for baseline CES-D score and other covariates, the metabolically unhealthy obese participants had elevated risk of depressive symptoms at follow-up (odds ratio (OR)=1.50; 95% confidence interval (CI), 1.05-2.15), although the metabolically healthy obese did not (OR=1.38; 95% CI, 0.88-2.17). The association between obesity and risk of depressive symptoms appears to be partly dependent on metabolic health, although further work is required to confirm these findings.
The authors aggregated the results of observational studies examining the association between long working hours and coronary heart disease (CHD). Data sources used were MEDLINE (through January 19, ...2011) and Web of Science (through March 14, 2011). Two investigators independently extracted results from eligible studies. Heterogeneity between the studies was assessed using the I(2) statistic, and the possibility of publication bias was assessed using the funnel plot and Egger's test for small-study effects. Twelve studies were identified (7 case-control, 4 prospective, and 1 cross-sectional). For a total of 22,518 participants (2,313 CHD cases), the minimally adjusted relative risk of CHD for long working hours was 1.80 (95% confidence interval (CI): 1.42, 2.29), and in the maximally (multivariate-) adjusted analysis the relative risk was 1.59 (95% CI: 1.23, 2.07). The 4 prospective studies produced a relative risk of 1.39 (95% CI: 1.12, 1.72), while the corresponding relative risk in the 7 case-control studies was 2.43 (95% CI: 1.81, 3.26). Little evidence of publication bias but relatively large heterogeneity was observed. Studies varied in size, design, measurement of exposure and outcome, and adjustments. In conclusion, results from prospective observational studies suggest an approximately 40% excess risk of CHD in employees working long hours.
Aims To determine the biological and behavioural factors linking work stress with coronary heart disease (CHD). Methods and results A total of 10 308 London-based male and female civil servants aged ...35–55 at phase 1 (1985–88) of the Whitehall II study were studied. Exposures included work stress (assessed at phases 1 and 2), and outcomes included behavioural risk factors (phase 3), the metabolic syndrome (phase 3), heart rate variability, morning rise in cortisol (phase 7), and incident CHD (phases 2–7) on the basis of CHD death, non-fatal myocardial infarction, or definite angina. Chronic work stress was associated with CHD and this association was stronger among participants aged under 50 (RR 1.68, 95% CI 1.17–2.42). There were similar associations between work stress and low physical activity, poor diet, the metabolic syndrome, its components, and lower heart rate variability. Cross-sectionally, work stress was associated with a higher morning rise in cortisol. Around 32% of the effect of work stress on CHD was attributable to its effect on health behaviours and the metabolic syndrome. Conclusion Work stress may be an important determinant of CHD among working-age populations, which is mediated through indirect effects on health behaviours and direct effects on neuroendocrine stress pathways.
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