Katri Sääksjärvi

Sociodemographic and socioeconomic differences in sleep duration and insomnia-related symptoms in Finnish adults

BackgroundPoor sleep tends to be patterned by sociodemographic and socioeconomic factors. The aim of this study was to examine the associations of sociodemographic and socioeconomic factors with sleep duration and insomnia-related symptoms across life course.MethodsWe used cross-sectional Health 2000 Survey (2000–2001) among a total of 5,578 adult Finns, aged 30–79 years, representative of adult Finnish population. Data about sociodemographic and socioeconomic circumstances, insomnia-related symptoms over the previous month as well as average sleep duration were collected by questionnaires. Multinomial logistic regression models were adjusted first for gender and age, second for sociodemographic factors, third additionally for socioeconomic factors, and fourth for all covariates and self-perceived health simultaneously.ResultsOn average 70% of Finnish adults slept 7–8 hours a day. Frequent insomnia-related symptoms were more prevalent among women (14%) than men (10%). Not being married, not having children, having low education, low income, being unemployed, and being a disability retiree were associated with frequent insomnia-related symptoms. Similar factors were associated with short and long sleep duration. However, childhood socioeconomic position was mostly unrelated to sleep in adulthood except parental education had some associations with short sleep duration.ConclusionsDisadvantaged socioeconomic position in adulthood, in particular income and employment status, is associated with poorer sleep. When promoting optimal sleep duration and better sleep quality, families with low incomes, unemployed people, and disability retirees should be targeted.

A cohort study on diet and the risk of Parkinson's disease: the role of food groups and diet quality

Previous studies on individual foods and nutrients and Parkinsons disease (PD) risk have been inconsistent. Furthermore, only one study has examined the association between the quality of diet and PD. We investigated the prediction of food groups and diet quality on PD in the Finnish Mobile Clinic Survey (1966-72). The population comprised 4524 individuals, aged 40-79 years and free from PD at baseline. Data collection included health examinations, a questionnaire and a 1-year dietary history interview. A modified Alternate Healthy Eating Index was formed to assess diet quality. Statistical analyses were based on Coxs model. During a 41-year follow-up, eighty-five incident cases of PD occurred. No statistically significant associations were found between PD incidence and most of the food groups examined. A few exceptions were fruits and berries in men and milk in women, which showed positive associations. An inverse association between the intake of meat products and PD was found in women. The diet quality index did not predict PD, the adjusted relative risk between the highest and lowest quartiles being 1.83 (95 % CI 0.65, 5.18) in men and 0.97 (95 % CI 0.38, 2.48) in women. The present study suggests that since most of the single food groups or the quality of diet did not predict PD occurrence, the role of diet is apparently rather modest.

Higher serum 25-hydroxyvitamin D concentrations are related to a reduced risk of depression.

Vitamin D has been suggested to protect against depression, but epidemiological evidence is scarce. The present study investigated the relationship of serum 25-hydroxyvitamin D (25(OH)D) with the prevalence of depressive and anxiety disorders. The study population consisted of a representative sample of Finnish men and women aged 30-79 years from the Health 2000 Survey. The sample included 5371 individuals, of which 354 were diagnosed with depressive disorder and 222 with anxiety disorder. Serum 25(OH)D concentration was determined from frozen samples. In a cross-sectional study, a total of four indicators of depression and one indicator of anxiety were used as dependent variables. Serum 25(OH)D was the risk factor of interest, and logistic models used further included sociodemographic and lifestyle variables as well as indicators of metabolic health as confounding and/or effect-modifying factors. The population attributable fraction (PAF) was estimated. Individuals with higher serum 25(OH)D concentrations showed a reduced risk of depression. The relative odds between the highest and lowest quartiles was 0.65 (95% CI 0.46, 0.93; P for trend = 0.006) after adjustment for sociodemographic, lifestyle and metabolic factors. Higher serum 25(OH)D concentrations were associated with a lower prevalence of depressive disorder especially among men, younger, divorced and those who had an unhealthy lifestyle or suffered from the metabolic syndrome. The PAF was estimated to be 19% for depression when serum 25(OH)D concentration was at least 50 nmol/l. These results support the hypothesis that higher serum 25(OH)D concentrations protect against depression even after adjustment for a large number of sociodemographic, lifestyle and metabolic factors. Large-scale prospective studies are needed to confirm this finding.

Serum 25-Hydroxyvitamin D Concentration and Risk of Dementia

Background: High vitamin D status has been hypothesized to protect against dementia. The aim of the current study was to investigate whether serum 25-hydroxyvitamin D (25(OH)D) level predicts dementia risk. Methods: The study was based on the Mini–Finland Health Survey. The study population consisted of 5010 men and women, aged 40–79 years, and free of dementia at baseline. During a 17-year follow up, 151 incident cases of dementia (International Classification of Diseases, revision 8, code 290) occurred, according to population registers. Serum 25(OH)D concentration was determined from serum samples frozen at −20°C and stored at baseline. Results: Among women, these with higher serum 25(OH)D concentrations showed a reduced risk of dementia. The hazard ratio between the highest and lowest quartiles of serum 25(OH)D was 0.33 (95% confidence interval = 0.15–0.73) in women and 0.74 (0.29–1.88) in men, after adjustment for age, month of blood draw, education, marital status, physical activity, smoking, alcohol consumption, body mass index, blood pressure, plasma fasting glucose, serum triglycerides, and serum total cholesterol. Conclusions: The results are in line with the hypothesis that low vitamin D status may be a risk factor for dementia.

Self-administered questionnaire is a reliable measure of coffee consumption.

Background The objective of this study was to assess the agreement and repeatability of 2 methods of measuring habitual coffee consumption, and to examine their homogeneity with respect to socioeconomic and lifestyle factors. Methods Data on coffee consumption were collected from 4254 subjects by means of a health questionnaire (HQ) and a 1-year dietary history interview (DHI), the latter of which was used as the reference method during the Finnish Mobile Clinic Health Examination Survey conducted in 1973–1976. Short-term repeatability of the methods was assessed using data from 286 and 93 subjects who repeated the HQ and the DHI, respectively, after an interval of 4 to 8 months. The strength of agreement between the 2 methods and between the repeated measurements was estimated using intraclass correlation coefficients (ICCs). Results The ICC was 0.86 for the agreement between the HQ and the DHI, and 0.77 and 0.85 for the repeatability of the HQ and the DHI, respectively. There were no statistically significant systematic differences in mean intake values between the 2 methods or between repeated measurements. In subgroup analysis of background variables, there were only minor differences in agreement and repeatability, with somewhat higher ICC values among subjects with a healthier lifestyle and higher education. Conclusions The high reliability and homogeneity of the health questionnaire make it a useful tool for measuring habitual coffee consumption for the purposes of epidemiological research.

Self-Administered Questionnaire Is a Reliable Measure of Coffee Consumption

Background The objective of this study was to assess the agreement and repeatability of 2 methods of measuring habitual coffee consumption, and to examine their homogeneity with respect to socioeconomic and lifestyle factors. Methods Data on coffee consumption were collected from 4254 subjects by means of a health questionnaire (HQ) and a 1-year dietary history interview (DHI), the latter of which was used as the reference method during the Finnish Mobile Clinic Health Examination Survey conducted in 1973–1976. Short-term repeatability of the methods was assessed using data from 286 and 93 subjects who repeated the HQ and the DHI, respectively, after an interval of 4 to 8 months. The strength of agreement between the 2 methods and between the repeated measurements was estimated using intraclass correlation coefficients (ICCs). Results The ICC was 0.86 for the agreement between the HQ and the DHI, and 0.77 and 0.85 for the repeatability of the HQ and the DHI, respectively. There were no statistically significant systematic differences in mean intake values between the 2 methods or between repeated measurements. In subgroup analysis of background variables, there were only minor differences in agreement and repeatability, with somewhat higher ICC values among subjects with a healthier lifestyle and higher education. Conclusions The high reliability and homogeneity of the health questionnaire make it a useful tool for measuring habitual coffee consumption for the purposes of epidemiological research.