Napping and the risk of type 2 diabetes: a population-based prospective study

OBJECTIVE: Some studies indicate an association between napping and increased risk of type 2 diabetes. We studied this prospectively in a sample representative of general population. METHODS: A questionnaire was administered to the Finnish Twin Cohort in 1990 (response rate 77%, age 33-60 years). The study population included 12,244 subjects who replied to the question "Do you sleep during the daytime (take naps)?" with five response alternatives ranging from "no need" to "every or almost every day." Information on incident cases of diabetes was obtained by linkage to nationwide registers. Logistic regression models were used to obtain odds ratios (ORs) (95% confidence intervals) for incident type 2 diabetes risk in 1991-2004 by napping category. Adjustments were made for 11 socio-demographic and lifestyle covariates. For subjects aged 33-45 years at baseline, a questionnaire in 2011 provided information on prevalent diabetes. RESULTS: Thirty-four per cent had no need for napping, and 15% did so on ≥3 days weekly. There were 356 incident type 2 diabetes cases during the follow-up. Using the 'no need' category as the reference, the risk of type 2 diabetes was significantly increased only among those napping most frequently [OR 1.86 (1.29-2.67), age- and sex-adjusted]. After adjusting for other covariates, the results were essentially the same, but when adjusted for body mass index, the association decreased (to about 1.3) and was statistically non-significant. Analysis of 2011 self-reported type 2 diabetes was in line with the register data. CONCLUSIONS: Frequent napping is associated with future risk of type 2 diabetes. This association is largely explained by obesity.Peer reviewe

Poor sleep predicts symptoms of depression and disability retirement due to depression

BACKGROUND: Disturbed sleep is associated with mood disorders. Both depression and insomnia may increase the risk of disability retirement. The longitudinal links among insomnia, depression and work incapacity are poorly known. METHODS: We examined association of self-reported sleep quality with incident symptoms of depression and disability retirement due to depressive disorders in a longitudinal population-based sample of twins (n=12,063 individuals). These adults were categorized by their sleep quality in 1975 and 1981, excluding individuals with depressed mood in 1975/1981. The outcomes were the Beck Depression Inventory (BDItot) and its subscale Negative Attitudes Towards Self (BDINATS) in 1990 as dichotomized measures, and the incidence of disability retirement due to depressive disorder during 1991-2004. RESULTS: Onset of poor sleep between 1975 and 1981 predicted incident depression (BDItot OR=4.5, 95% CI: 2.7-7.4, BDINATS OR=2.0, 95% CI: 1.4-2.7), while persistent poor sleep showed somewhat weaker effects (BDItot; OR=2.5, 95% CI: 1.0-6.0, BDINATS OR=1.9, 95% CI: 1.1-3.3). Among those with few recent stressful life events, onset of poor sleep predicted strongly depression (BDINATS OR=9.5, 95% CI: 3.7-24.2). Likewise onset of poor sleep by 1981 increased the risk of disability retirement due to depression (OR=2.9, 95% CI: 1.8-4.9) with a similar risk among those with persistent poor sleep (OR=2.7, 95% CI: 1.3-5.7). LIMITATIONS: Lack of baseline diagnostic interviews; sleep quality based on self-report. CONCLUSIONS: Poor sleep is of importance in etiology of depression and disability retirement due to depression. This emphasizes the importance of early detection and treatment of sleep disturbances.Peer reviewe

Occurrence of symptoms and depressive mood among working-aged coronary heart disease patients

BACKGROUND: The typical symptoms of coronary heart disease (CHD), chest pain and breathlessness, are well-known. They are considered quite dramatic, and can thus be fairly reliably mapped by a survey. However, people might have other clearly unpleasant symptoms impairing quality of life. The aim of this study is to evaluate the appearance of these complaints of working-aged people with self-reported CHD. METHODS: The study consists of a postal questionnaire of randomly selected Finns in age groups 30–34, 40–44 and 50–54, a response rate of 39% (N = 15,477). The subjects were asked whether or not a doctor had told them that they had angina pectoris or had had myocardial infarction. Four randomly selected age and sex matched controls were chosen for every patient. The occurrence of self-reported dyspnoea, chest pain during anger or other kind of emotion, palpitation and perspiration without physical exercise, irregular heartbeats, flushing, trembling of hands and voice, jerking of muscles, depression and day-time sleepiness were examined. Odds ratios (OR) with 95% confidence intervals (CI), between occurrence of symptoms and CHD with and without heart infarction, were computed by multivariate logistic regression analysis. RESULTS: The sample eventually comprised 319 CHD patients. Dyspnoea, chest pain during anger or other kind of emotion, palpitation, perspiration without physical exercise, irregular heartbeats daily or almost daily, trembling of hands and voice, and jerking of muscles occurred statistically significantly more frequently among CHD patients than among controls. The CHD patients also reported more depressive mood according to Beck's inventory scores and poorer sleep and more frequent day-time sleepiness than controls. In the multivariate logistic regression analysis chest pain during anger or other kind of emotion (ORs 4.12 and 3.61) and dyspnoea (ORs 2.33 and 3.81) were the symptoms most associated with CHD. CONCLUSIONS: Working-aged people with self-reported coronary heart disease evince a number of symptoms limiting the quality of their every day life. This aspect should be paid attention to when evaluating functional capacity of these patients

Impact of major life events on breast-cancer-specific mortality : A case fatality study on 8000 breast cancer patients

Background: It has been suggested that long-term activation of the body's stress-response system and subsequent overexposure to stress hormones may be associated with increased morbidity. However, evidence on the impact of major life events on mortality from breast cancer (BC) remains inconclusive. The main aim of this study is to investigate whether major negatively or positively experienced life events before or after diagnosis have an effect on BC-specific mortality in women who have survived with BC for at least 2 years. Methods: We conducted a case fatality study with data on life events from a self-administered survey and data on BC from the Finnish Cancer Registry. Cox models were fitted to estimate BC mortality hazard ratios (MRs) between those who have undergone major life events and those who haven't. Results: None of the pre-diagnostic negative life events had any effect on BC-specific mortality. Regarding post-diagnostic events, the effect was greatest in women with moderate scores of events. As for event-specific scores, increased BC mortality was observed with spouse unemployment, relationship problems, and death of a close friend. By contrast, falling in love and positive developments in hobbies were shown to be associated with lower BC mortality (MRs 0.67, 95% CI: 0.49-0.92 and 0.74, 95% CI: 0.57-0.96, respectively). In an analysis restricted to recently diagnosed cases (2007), also death of a child and of a mother was associated with increased BC mortality. Conclusions: Some major life events regarding close personal relationships may play a role in BC-specific mortality, with certain negative life events increasing BC mortality and positive events decreasing it. The observed favorable associations between positive developments in romantic relationships and hobbies and BC mortality are likely to reflect the importance of social interaction and support. (C) 2017 Elsevier Ltd. All rights reserved.Peer reviewe

Best friend's and family members' smoking habits and parental divorce during childhood are associated with smoking in adulthood

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Stability and change of body mass index as a predictor of disability

AIMS: To investigate whether stability or change in body mass index (BMI) predict disability pension (DP) due to musculoskeletal diagnosis (MSD) when controlling for familial confounding. METHODS: Our study cohort consisted of 17,169 Finnish twins born before 1958. Data on BMI and multiple covariates from questionnaires in 1975 and 1981 were included and DPs were collected from the national pension registers until the end of 2004. Cox proportional hazards regression models with Hazard Ratios (HR) and 95% Confidence Intervals (CI) were used for statistical analyses. RESULTS: General DP was granted to 2853 individuals and DP due to MSD to 1143 individuals during the 23-year follow-up. A one-unit increase in BMI in both 1975 (HR 1.08, 95% CI 1.05, 1.10) and 1981 (HR 1.06, 95% CI 1.04, 1.07), as well as the stability of and change in BMI from 1975 to 1981 were all associated with an increased risk of DP. These associations held in the analyses controlling for multiple covariates (age, sex, socioeconomic status, education, marital status, leisure-time physical activity, and musculoskeletal pain), and mainly also familial confounding, that is, genetics and shared environment. HR for stable obesity was 2.28 (95% CI 1.69, 3.08) for DP due to MSD, and 1.91 (95% CI 1.56, 2.34) for general DP in the fully adjusted models. CONCLUSIONS: BMI is an early predictor of general DP and also of DP due to MSD. Owing to the independency of various covariates and potentially also familial confounding, BMI may possibly have a direct effect on the risk of DP.Peer reviewe