In the present study, we evaluated whether childhood differences in body height between singletons and twins persist into adulthood. Data from the Medical Birth Register of Norway were linked with data from the Norwegian National Conscript Service. This study used data on the 457,999 males who were born alive and without physical anomalies in single or twin births in Norway during 1967-1984 and who were examined at the mandatory military conscription (age 18-20 years; 1985-2003). For sibling comparisons, the authors selected the 1,721 sibships of full brothers that included at least 1 male born in a single birth and at least 1 male born in a twin birth (4,520 persons, including 2,493 twins and 2,027 singletons). An analysis of the total study population using generalized estimating equations showed that the twins were 0.6 cm (95% confidence interval: 0.4, 0.7) shorter than were the singletons after adjustment for a series of background factors. The fixed-effects regression analysis of the sibships that included both twins and singletons showed that the twins were 0.9 cm (95% confidence interval: 0.6, 1.2) shorter than were their singleton brothers. The study suggests that male twins born in Norway during 1967-1984 were slightly shorter in early adulthood than were singletons.
An inverse relationship between educational level and dementia has been reported in several studies. In this study we investigated the relationship between educational level and dementia related deaths for cohorts of people all born during 1915-39. The cohorts were followed up from adulthood or old age, taking into account possible confounders and mediating paths. Our study population comprised participants in Norwegian health examination studies in the period 1974-2002; The Counties Study and Cohort of Norway (CONOR). Dementia related deaths were defined as deaths with a dementia diagnosis on the death certificate and linked using the Cause of Death Registry to year 2012. The study included 90,843 participants, 2.06 million person years and 2440 dementia related deaths. Cox regression was used to assess the association between education and dementia related deaths. Both high and middle educational levels were associated with lower dementia related death risk compared to those with low education when follow-up started in adulthood (35-49 years, high versus low education: HR=0.68, 95% confidence interval (CI) 0.50-0.93; 50-69 years, high versus low education: HR=0.52, 95% CI 0.34-0.80). However, when follow-up started at old age (70-80 years) there was no significant association between education and dementia related death. Restricting the study population to those born during a five-year period 1925-29 (the birth cohort overlapping all three age groups), gave similar main findings. The protective effects found for both high and middle educational level compared to low education were robust to adjustment for cardiovascular health and life style factors, suggesting education to be a protective factor for dementia related death. Both high and middle educational levels were associated with decreased dementia related death risk compared with low educational level when follow-up started in adulthood, but no association was observed when follow-up started at old age.
This study tested the hypothesis that moderate alcohol intake exerts its cardioprotective effect mainly through an increase in the serum level of high-density lipoprotein cholesterol.
In the Cohort of Norway (CONOR) study, 149 729 adult participants, recruited from 1994 to 2003, were followed by linkage to the Cause of Death Registry until 2006. At recruitment, questionnaire data on alcohol intake were collected, and the concentration of high-density lipoprotein cholesterol in serum was measured. Using Cox regression, we found that the adjusted hazard ratio for men for dying from coronary heart disease was 0.52 (95% confidence interval, 0.39-0.69) when consuming alcohol more than once a week compared with never or rarely. The ratio changed only slightly, to 0.55 (0.41-0.73), after the regression model included the serum level of high-density cholesterol. For women, the corresponding hazard ratios were 0.62 (0.32-1.23) and 0.68 (0.34-1.34), respectively.
Alcohol intake is related to a reduced risk of death from coronary heart disease in the follow-up of a large, population-based Norwegian cohort study with extensive control for confounding factors. Our findings suggest that the serum level of high-density cholesterol is not an important intermediate variable in the possible causal pathway between moderate alcohol intake and coronary heart disease.
Comment In: Circulation. 2011 Nov 22;124(21):2283-422105194
There is growing evidence that midlife risk factors for vascular disease also are risk factors for dementia, but there is still need for long-term observational studies to address this. Our objective was to investigate the association of midlife vascular disease risk factors with dementia death. Participants were included in The Norwegian Counties Study (NCS) in the period 1974-78, aged 35-50 years at baseline. Information from NCS was linked with the Cause of Death Registry through the year 2009 using the unique personal identification number. The study included 48,793 participants, 1.5 million person years and 486 dementia deaths (187 Alzheimer's; 299 non-Alzheimer's dementia). Cox regression for cause-specific hazards was used. Dementia death was associated with increased total cholesterol levels (>7.80 vs.
OBJECTIVE: To estimate effects of hearing loss on symptoms of anxiety, depression, self-esteem, and subjective well-being. METHODS: A normal population sample of 50,398 subjects, age 20 to 101 years, in Nord-Trøndelag completed audiometric tests and questionnaires. The association between hearing loss and mental health was assessed with multiple linear regression analyses, controlling for social background variables. RESULTS: Effects of hearing loss were mostly significant, but moderate in strength. Effects were stronger among young (20-44 years) and middle-aged (45-64 years) than among older (65+ years) people. Loss of high or middle frequency hearing had almost no impact on mental health measures if low frequency hearing was not also impaired. The strongest observed effect was a change of 0.1 SD in mental health per 10 dB hearing loss. CONCLUSIONS: Hearing loss is associated with substantially reduced mental health ratings among some young and middle-aged persons, but usually does not affect mental health much among older persons.
This study examined the association between time of onset of hearing loss (childhood vs. adulthood) and self-reported hearing handicap in adults.
This is a population-based cohort study of 2,024 adults (mean = 48 years) with hearing loss (binaural pure-tone average 0.5-4 kHz = 20 dB HL) who completed a hearing handicap questionnaire. In childhood, the same persons (N = 2,024) underwent audiometry in a school investigation (at ages 7, 10, and 13 years), in which 129 were diagnosed with sensorineural hearing loss (binaural pure-tone average 0.5-4 kHz = 20 dB HL), whereas 1,895 had normal hearing thresholds.
Hearing handicap was measured in adulthood as the sum-score of various speech perception and social impairment items (15 items). The sum-score increased with adult hearing threshold level (p
Cites: J Oslo City Hosp. 1968 Jan-Feb;18(1):5-444865929
Behavioural and neuropsychological vulnerability have been associated with an increased risk of psychosis. We investigated whether certain clusters of premorbid behavioural and personality-related signs and symptoms were predictors of nonaffective and/or affective psychosis and schizophrenia, respectively, in a 50-year follow-up of an unselected general community population. Total population cohorts from the same catchment area in 1947 (n = 2,503) and 1957 (n = 3,215) that had been rated for behavioural items and enduring symptoms were followed up to 1997 regarding first-incidence of DSM-IV nonaffective and/or affective psychosis. Attrition was 1-6%. The influence of the background factors, aggregated in dichotomous variables (predictors), on time to occurrence of nonaffective and/or affective psychosis was assessed by means of Cox regression models. In multivariate models the predictors nervous-tense, blunt-deteriorated, paranoid-schizotypal and tired-distracted were significantly associated with subsequent nonaffective and/or affective psychosis. In simple models, down-semidepressed, sensitive-frail and easily hurt were significantly associated with development of psychosis. When schizophrenia was analysed separately nervous-tense remained significant in the multivariate model, although blunt-deteriorated, paranoid-schizotypal and tired-distracted did not; and abnormal-antisocial reached significance. To conclude, we found some evidence for anxiety-proneness, affective/cognitive blunting, poor concentration, personality cluster-A like traits and interpersonal sensitivity to be associated with general psychosis vulnerability.
The study aimed to investigate potential adolescent and parental psychosocial risk and protective factors for psychological distress among adolescents and, in addition, to examine potential gender and age differences in the effects of risk factors on adolescent psychological distress.
Data were collected among 8,984 Norwegian adolescents (13-19 years) and their parents in the Nord-Trøndelag Health Study (HUNT). The outcome measure was psychological distress (SCL-5).
Bivariate regression analysis with generalized estimating equation (GEE) model showed that all parental self-reported variables (mental distress, substance use, social network, economic problems, unemployment and family structure) and adolescents' self-reported variables (leisure activities, social support from friends, school-related problems and substance use) were significantly associated with psychological distress among adolescents. Results revealed that in a multiple regression analysis with a GEE model, adolescent psychosocial variables, specifically academic-related problems and being bullied at school, emerged as the strongest predictors of psychological distress among adolescents after controlling for age, gender, and all parental and adolescent variables. The following psychosocial risk factors were significantly more important for girl's psychological distress compared to boys: problems with academic achievement, conduct problems in school, frequency of being drunk, smoking, dissatisfaction in school, living alone and seen parents being drunk.
Academic achievement and being bullied at school were the psychosocial factors most strongly associated with psychological distress among adolescents. Parental factors had an indirect effect on adolescent psychological distress, through adolescents' psychosocial factors.
Self-report scales for symptoms of anxiety and depression are frequently used for screening and research purposes. A moderate phenotypic association between disorders measured by diagnostic interviews and symptoms of anxiety and depression measured by self-report scales has been shown, but little is known about the overlap in these phenotypes' genetic and environmental variance. In the present study, we used twin modeling to identify common genetic and environmental liabilities underlying the phenotypic association between the self-report Symptom Checklist-5 (SCL-5) and lifetime internalizing disorders derived from the Composite International Diagnostic Interview (CIDI). The sample consisted of 7,992 young adult twins from the Norwegian Institute of Public Health Twin Panel (NIPHT), who all responded to a questionnaire. A subset of 2,793 individuals later underwent structured interviews. The best fitting model showed a strong genetic correlation of 0.82 (95% confidence interval; 0.61-1.0) between current self-report symptoms of anxiety and depression, and lifetime internalizing disorders, which suggests an almost complete overlap in genetic liability. The correlation between environmental factors was much lower: 0.16 (0.00-0.34, 95% CI). This implies that brief self-report scales capture genetic variance that is highly overlapping with the genetic variance common to internalizing disorder diagnoses. It thus follows that SCL-5 and similar instruments may be used as screening instruments for genetic risk factors that influence liability to internalizing disorders. In addition, existing data on self-report symptoms of anxiety and depression can be used with increased confidence to specify models including effects from genes coding for internalizing disorders.
Cites: Am J Psychiatry. 2000 Oct;157(10):1552-6211007705
Cites: Am J Psychiatry. 2001 Jul;158(7):1091-811431231
Cites: Am J Psychiatry. 2001 Oct;158(10):1568-7811578982