Jukka Montonen

Serum vitamin D and subsequent occurrence of type 2 diabetes.

Background: Low vitamin D status has been suggested as a risk factor for type 2 diabetes. Although the epidemiologic evidence is scarce, 2 recent studies have suggested an association. The present study investigated the relation of serum vitamin D with type 2 diabetes incidence using pooled data from these 2 cohorts. Methods: Two nested case-control studies, collected by the Finnish Mobile Clinic in 1973–1980, were pooled for analysis. The study populations consisted of men and women aged 40–74 years and free of diabetes at baseline. During a follow-up period of 22 years, 412 incident type 2 diabetes cases occurred, and 986 controls were selected by individual matching. Serum vitamin D (serum 25(OH)D) was determined from frozen samples, stored at baseline. Pooled estimates of the relationship between serum vitamin D concentration and type 2 diabetes incidence were calculated. Results: Men had higher serum vitamin D concentrations than women and showed a reduced risk of type 2 diabetes in their highest vitamin D quartile. The relative odds between the highest and lowest quartiles was 0.28 (95% confidence interval = 0.10–0.81) in men and 1.14 (0.60–2.17) in women after adjustment for smoking, body mass index, physical activity, and education. Conclusions: The results support the hypothesis that high vitamin D status provides protection against type 2 diabetes. Residual confounding may contribute to this association.

Plant foods and the risk of cerebrovascular diseases: a potential protection of fruit consumption

Studies on the association between plant foods and cerebrovascular diseases have given contradictory results suggesting the existence of some effect-modifying factors. The present study determines whether the consumption of plant foods (i.e. fruits and berries, vegetables, and cereals) predicts a decreased cerebrovascular disease incidence in a population with low fruit and vegetable and high wholegrain intake. This cohort study on 3932 men and women was based on data from the Finnish Mobile Clinic Health Examination Survey, conducted in 1968-72. The participants were 40-74 years of age and free of cardiovascular diseases at baseline. Data on the plant food consumption were derived from a 1-year dietary history interview. During a 24-year follow-up 625 cases of cerebrovascular diseases occurred, leading to either hospitalisation or death. An inverse association was found between fruit consumption and the incidence of cerebrovascular diseases, ischaemic stroke and intracerebral haemorrhage. The adjusted relative risks (RR) between the highest and lowest quartiles of intake of any cerebrovascular disease, ischaemic stroke and intracerebral haemorrhage were 0.75 (95 % CI 0.59, 0.94), 0.73 (95 % CI 0.54, 1.00) and 0.47 (95 % CI 0.24, 0.92), respectively. These associations were primarily due to the consumption of citrus fruits and occurred only in men. Total consumption of vegetables or cereals was not associated with the cerebrovascular disease incidence. The consumption of cruciferous vegetables, however, predicted a reduced risk of cerebrovascular diseases (RR 0.79; 95 % CI 0.63, 0.99), ischaemic stroke (RR 0.67; 95 % CI 0.49, 0.92) and intracerebral haemorrhage (RR 0.49; 95 % CI 0.25, 0.98). In conclusion, the consumption of fruits, especially citrus, and cruciferous vegetables may protect against cerebrovascular diseases.

Malignancies in cases with screening-identified evidence of coeliac disease: a long-term population-based cohort study

Background and aims: The association between diagnosed coeliac disease and malignancy has been established. The present study was conducted to determine whether previously unrecognised and thus untreated adults with screening-identified evidence of coeliac disease carry an increased risk of malignancies. Methods: A Finnish population-based adult-representative cohort of 8000 individuals was drawn in 1978–1980. Stored sera of the participants with no history of coeliac disease or any malignancy were tested for immunoglobulin A (IgA) class tissue transglutaminase antibodies (Eu-tTG) in 2001. Positive sera were further analysed by another tissue transglutaminase antibody test (Celikey tTG) and for endomysial antibodies (EMAs). Malignant diseases were extracted from the nationwide database and antibody-positive cases were compared with negative cases during a follow-up of nearly 20 years. Results: Altogether 565 of all the 6849 analysed serum samples drawn in 1978–80 were Eu-tTG positive. In further analyses, 202 (2.9%) of the participants were Celikey tTG positive and 73 (1.1%) were EMA positive. The overall risk of malignancy was not increased among antibody-positive cases in the follow-up of two decades; the age- and sex-adjusted relative risk was 0.91 (95% CI 0.60 to 1.37) for those who were Celikey tTG positive and 0.67 (95% CI 0.28 to 1.61) for those who were EMA positive. Conclusions: The prognosis of adults with unrecognised coeliac disease with positive coeliac disease antibody status is good as regards the overall risk of malignancies. Thus, current diagnostic practice is sufficient and there is no need for earlier diagnosis of coeliac disease by mass screening on the basis of the findings of this study.

Vitamin D status and common risk factors for bone fragility as determinants of quantitative ultrasound variables in a nationally representative population sample.

Calcaneal quantitative ultrasound (QUS) can predict bone strength and fracture risk. Bone fragility has no single cause but results from a complex interplay of several etiologic or contributing factors. Vitamin D is essential for bone health even though it is still unclear how much of this vitamin is required to maintain bone strength and prevent fractures. Measurements of serum 25-hydroxyvitamin D [S-25(OH)D] have indicated a high prevalence of inadequate vitamin D status in a number of studies mostly based on selected study populations. The objective of this study was to examine the associations between S-25(OH)D, common risk factors for bone fragility, and QUS variables in a large unselected population sample. The study population consisted of 2736 men and 3299 women from a nationally representative population sample, aged 30 years or over. Information on lifestyle was elicited by means of interviews and questionnaires. Body fat mass was estimated using an impedance-meter. S-25(OH)D was measured by radioimmunoassay. Calcaneal QUS was performed on the Hologic Sahara apparatus recording broadband ultrasound attenuation (BUA) and speed of sound (SOS). The potential determinants of BUA and SOS were analysed using separate multiple linear regression models for men and women. S-25(OH)D proved to be an independent determinant of BUA (P<0.0001 for men, P<0.001 for women) and SOS (P<0.0001 for men, P<0.05 for women). BUA was also independently associated with age, height, weight, alcohol consumption, and postmenopausal status in women, and with weight, alcohol consumption, smoking and physical activity in men. All of the above variables, except for weight in women, were also found to be independent determinants of SOS in both men and women. A reverse association was found between S-25(OH)D and adiposity in spite of higher intakes of vitamin D in those with higher fat mass. In this unselected sample of men and women, vitamin D status, several lifestyle factors and physical characteristics proved to be significant determinants of BUA and SOS. Inadequate vitamin D status was common, and measures ensuring adequate intakes of vitamin D in the population thus deserve continued attention. Obesity should be taken into account in future assessments of vitamin D status in Finland as in other countries.

Fish consumption and the incidence of cerebrovascular disease

Studies of the beneficial role of fish consumption in the prevention of CVD are not consistent in their findings, particularly those studies that focus on the risk of stroke. The aim of the present study is to investigate the relationship between the consumption of different types of fish and the subsequent incidence of cerebrovascular disease (CVA). We prospectively evaluated the association between consumption of different types of fish and CVA in 3958 men and women aged 40-79 years who were free of heart disease and had participated in a health examination survey from 1967 to 1972. A total of 659 incident cases of CVA occurred during a follow-up until the end of 1994. A dietary history interview method provided data on habitual consumption of fish and other foods over the preceding year at baseline. Total fish intake did not predict CVA, but consumption of salted fish suggested an increased risk of intracerebral haemorrhage. The relative risk of intracerebral haemorrhage between the highest tertile of salted fish consumption and non-consumers was 1.98 (95 % CI 1.02, 3.84; P for trend = 0.06) after adjustment for age, sex, energy intake, smoking, BMI, physical activity, geographic area, occupation, diabetes, use of post-menopausal hormones, serum cholesterol, hypertension, and consumptions of butter, vegetables, fruits and berries. The relationship between fish consumption and stroke risk is not straightforward. How the fish is prepared for consumption may play an important role, affecting the association.

Fish consumption and polyunsaturated fatty acids in relation to psychological distress

BACKGROUND It has been suggested that high fish consumption improves mental well-being. The aim of this study was to assess whether high fish consumption or omega-3 polyunsaturated fatty acid (PUFA) intake was associated with reduced self-reported psychological distress. METHODS We used three cross-sectional data sets, the nationwide Health 2000 Survey (n = 5840), the Fishermen Study on Finnish fishermen and their family members (n = 1282) and the Finntwin16 Study on young adults (n = 4986). Data were based on self-administered questionnaires, interviews, health examinations and blood samples. Psychological distress was measured using the 12-item and 21-item General Health Questionnaires (GHQs). Fish consumption was measured by a food frequency questionnaire (FFQ, g/day) and independent frequency questions (times/month). Dietary intake (g/day) and serum concentrations (% from fatty acids) of PUFAs were determined. Relationships were analysed using regression analysis. RESULTS Regardless of the measure, fish consumption and omega-3 PUFA dietary intake were not associated with distress in any of the data sets. In contrast to the hypothesis, high serum docosahexaenoic acid was associated with high distress in the Fisherman Study men. Some non-linear associations were detected between serum omega-3 PUFAs or fish consumption (times/month) and distress. In the Fishermen Study, the associations were modified by alcohol consumption, smoking and physical activity. CONCLUSIONS Our results do not support the hypothesis that fish consumption or omega-3 PUFA intake are associated with reduced psychological distress in the general population or in a population with high fish consumption.

Difference in diet between a general population national representative sample and individuals with alcohol use disorders, but not individuals with depressive or anxiety disorders

Abstract Background: Mental disorders influence diet and food consumption, but there is a lack of consistent findings. Aims: To investigate food consumption, nutrient intakes and serum metabolic biomarkers in depressive, anxiety and alcohol use disorders in comparison with the remaining from a population-based nationwide sample. Methods: The study was based on the Health 2000 Survey data of which 5504 subjects aged 30 and over (3009 women and 2495 men) were used for the analysis. Depressive disorder, anxiety disorders and alcohol use disorders were diagnosed using the Composite International Diagnostic Interview (M-CIDI). The consumption of food and beverage items, and nutrient intakes were measured with a validated food frequency questionnaire, and the concentrations of biomarkers were determined in blood samples. Results: Overall, no similar differences with both genders were found in the intakes of energy, dietary fibre or macronutrients or in biomarkers in depressive or anxiety disorders. Women suffering from depressed disorder consumed more soft drinks (P = 0.034) and women suffering from anxiety disorders consumed more oils (P = 0.001), polyunsaturated fatty acids (P = 0.001) and less potatoes (P = 0.002) than the remaining participants. Men suffering from depressive disorder consumed less sweets and chocolate (P = 0.001) and men with anxiety disorder consumed more tea (P = 0.033) compared with the remaining participants. In alcohol use disorders, the intake of carbohydrate was lower in both genders (P = 0.001 for women, P = 0.001 for men). Conclusions: A difference in the usual diet exists between individuals with alcohol use disorders and the remaining participants on a population level. No consistent difference in both genders between those with depressive or anxiety disorders and the remaining was found.