General Population-based Northern Finland Birth Research Articles

School success in childhood and subsequent prodromal symptoms and psychoses in the Northern Finland Birth Cohort 1986.

Low IQ is a risk factor for psychosis, but the effect of high IQ is more controversial. The aim was to explore the association of childhood school success with prodromal symptoms in adolescence and psychoses in adulthood. In the general population-based Northern Finland Birth Cohort 1986 (n = 8 229), we studied the relationship between teacher-assessed learning deficits, special talents and general school success at age 8 years and both prodromal symptoms (PROD-screen) at age 15-16 years and the occurrence of psychoses by age 30 years. More prodromal symptoms were experienced by those talented in oral presentation [boys: adjusted odds ratio (OR) 1.49; 95% confidence interval 1.14-1.96; girls: 1.23; 1.00-1.52] or drawing (boys: 1.44; 1.10-1.87). Conversely, being talented in athletics decreased the probability of psychotic-like symptoms (boys: OR 0.72; 0.58-0.90). School success below average predicted less prodromal symptoms with boys (OR 0.68; 0.48-0.97), whereas above-average success predicted more prodromal symptoms with girls (OR 1.22; 1.03-1.44). The occurrence of psychoses was not affected. Learning deficits did not associate with prodromal symptoms or psychoses. Learning deficits in childhood did not increase the risk of prodromal symptoms in adolescence or later psychosis in this large birth cohort. Learning deficits are not always associated with increased risk of psychosis, which might be due to, e.g. special support given in schools. The higher prevalence of prodromal symptoms in talented children may reflect a different kind of relationship of school success with prodromal symptoms compared to full psychoses.

Adolescent cannabis use, baseline prodromal symptoms and the risk of psychosis.

The association between cannabis use and the risk of psychosis has been studied extensively but the temporal order still remains controversial. Aims To examine the association between cannabis use in adolescence and the risk of psychosis after adjustment for prodromal symptoms and other potential confounders. The sample (n = 6534) was composed of the prospective general population-based Northern Finland Birth Cohort of 1986. Information on prodromal symptoms of psychosis and cannabis use was collected using questionnaires at age 15-16 years. Participants were followed up for ICD-10 psychotic disorders until age 30 years using nationwide registers. The risk of psychosis was elevated in individuals who had tried cannabis five times or more (hazard ratio, (HR) = 6.5, 95% CI 3.0-13.9). The association remained statistically significant even when adjusted for prodromal symptoms, other substance use and parental psychosis (HR = 3.0, 95% CI 1.1-8.0). Adolescent cannabis use is associated with increased risk of psychosis even after adjustment for baseline prodromal symptoms, parental psychosis and other substance use. Declaration of interest None.

Body mass index and brain white matter structure in young adults at risk for psychosis – The Oulu Brain and Mind Study

Antipsychotic medications and psychotic illness related factors may affect both weight and brain structure in people with psychosis. Genetically high-risk individuals offer an opportunity to study the relationship between body mass index (BMI) and brain structure free from these potential confounds. We examined the effect of BMI on white matter (WM) microstructure in subjects with familial risk for psychosis (FR). We used diffusion tensor imaging and tract-based spatial statistics to explore the effect of BMI on whole brain FA in 42 (13 males) participants with FR and 46 (16 males) control participants aged 20–25 years drawn from general population-based Northern Finland Birth Cohort 1986. We also measured axial, radial and mean diffusivities. Most of the participants were normal weight rather than obese. In the FR group, decrease in fractional anisotropy and increase in radial diffusivity were associated with an increase in BMI in several brain areas. In controls the opposite pattern was seen in participants with higher BMI. There was a statistically significant interaction between group and BMI on FA and radial and mean diffusivities. Our results suggest that the effect of BMI on WM differs between individuals with FR for psychosis and controls.

Pain‐related symptoms of temporomandibular disorders in the offspring of antenatally depressed mothers and depressed parents: A 31‐year follow‐up of the Northern Finland Birth Cohort 1966

Temporomandibular disorders (TMDs) are clinical problems involving the masticatory muscles and temporomandibular joints (TMJs). Aspects of the aetiology of TMD are controversial. Many studies have identified an association between depression and TMD. The aim of the study was to evaluate the association between both maternal antenatal depression and parental depression during the offspring's childhood with TMD symptoms of the offspring during adulthood and to evaluate the effect of the offspring's own depression on this association. In the general population-based Northern Finland Birth Cohort 1966 (NFBC 1966), mothers of 12,058 children were asked at mid-gestation at the antenatal clinic if they felt depressed. Of these offspring who had data available on TMD symptoms in the computer-aided inquiry at the 31-year field study, a final study data of 5541 subjects was compiled. The Finnish Hospital Discharge Register was used to identify depression in the parents between the years 1972 and 1984 (when offspring were 6-18 years old). There were no statistically significant associations between TMD symptoms and maternal antenatal depressed mood. However, parental depression during the offspring's childhood associated significantly with facial pain [adjusted odds ratio (OR) = 1.64; 1.05-2.56] and with TMJ pain at jaw rest (OR = 1.81; 1.13-2.89), even after adjusting for gender, occupation of the father, family type at birth and the offspring's self-reported depression in adulthood. The risk for TMD symptoms is not elevated in the offspring of antenatally depressed mothers. Parental depression during an offspring's childhood increases the risk of pain-related TMD symptoms in their early adulthood.

Young people at risk for psychosis: case finding and sample characteristics of the Oulu Brain and Mind Study

Set within the general population-based Northern Finland Birth Cohort 1986, the Oulu Brain and Mind Study aims to explore the causes and pathogenesis of psychotic illness by following young people at risk for psychosis due to having a first-degree relative with psychotic illness or due to having experienced psychotic-like symptoms themselves. We report the study methods and explore the relationship between these definitions of high risk for psychosis and operational criteria for a prodromal psychosis syndrome based on interview. Prospectively collected data from earlier follow-ups of this cohort were combined with health register data to categorize subjects as those with familial risk (n = 272), symptomatic risk (n = 117), psychosis (n = 78), attention deficit hyperactivity disorder (ADHD) (n = 103) and a sample of controls (n = 193) drawn randomly from the remaining cohort. The Structured Interview for Prodromal Syndromes (SIPS) was applied to all, 295 participants together with questionnaires measuring psychosis vulnerability and schizotypal traits. There were 29 (10%) current prodromal cases. Criteria for the current prodromal syndrome were fulfilled by 12% of the familial risk group and 19% of the symptomatic risk group, compared with 5% of the ADHD group and 4% of controls. We successfully detected young people with a prodromal psychosis syndrome although relatively few subjects deemed to be at high risk met the full operational criteria according to the SIPS interview. Combining methods from familial, clinical and psychometric high-risk approaches provides a tractable method for studying risk of psychosis in the general population.

Intergenerational transmission of overweight among Finnish adolescents and their parents: a 16-year follow-up study

Previous studies have shown strong parental influences on adolescent overweight. However, longitudinal data is scarce on gender-specific effects of parental body mass index (BMI) on offspring overweight. The objective of this study was to examine the associations of parental pre-pregnancy BMI, weight change, BMI and BMI class transition 16 years after pregnancy with the BMI of their 16-year-old children. The study population was derived from the general population-based Northern Finland Birth Cohort 1986. A total of 4788 child-mother-father trios (2325 boys, 2463 girls) were analysed. Weight and height of the adolescents were measured and overweight and obesity defined according to the International Obesity Task Force. For the parents, self-reported data were obtained and overweight and obesity defined according to the World Health Organization. Associations of parental BMI status and weight change with offspring BMI were assessed using binary logistic regression analyses stratified by gender and adjusted for parental age and education. Children whose both parents were overweight or obese both before pregnancy and after 16-year follow-up had a strikingly high risk of overweight at age 16 years (boys odds ratio (OR) 5.66 95% confidence interval (CI) 3.12, 10.27; girls OR 14.84 95% CI 7.41, 29.73). Parental pre-pregnancy obesity strongly predicted offspring overweight (mother-son OR 4.36 95% CI 2.50, 7.59; mother-daughter OR 3.95 95% CI 2.34, 6.68; father-son OR 3.17 95% CI 1.70, 5.92; father-daughter OR 5.58 95% CI 3.09, 10.07). Parental overweight conveys a major risk for overweight in children for which both parents' long-term overweight (BMI ≥25 kg m(-2) before pregnancy and after 16-year follow-up) was the strongest single predictor. Preventing intergenerational transmission of obesity by helping parents to maintain a healthy weight is an essential target for public health.

Chlamydia antibodies and self-reported symptoms of oligo-amenorrhea and hirsutism: A new etiologic factor in polycystic ovary syndrome?

To investigate whether the systemic inflammation induced by chlamydial infections might be associated with symptoms of polycystic ovary syndrome (PCOS). Nested case-control study. A questionnaire including questions about hirsutism and oligo-amenorrhea was distributed to a representative sample of women (at age 31) from the general population-based Northern Finland Birth Cohort. Those who reported both symptoms were defined as symptomatic (n=81). A representative sample of women (at age 31) from the general population-based Northern Finland Birth Cohort. None. To test the presence of serum antibodies to Chlamydia pneumoniae (IgG titers ≥32) and Chlamydia trachomatis (IgG titers ≥8) by microimmunofluorescence in symptomatic and control women. Antibodies were investigated in 79 symptomatic and 1427 control women (C. pneumoniae) and in 79 symptomatic and 425 control women (C trachomatis). C. trachomatis antibodies (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.3-4.6) and C. pneumoniae antibodies (OR, 1.5; 95% CI, 1.0-2.4) were more commonly present in symptomatic women, and the simultaneous presence of elevated highly sensitive C-reactive protein levels strengthened this association. Chronic inflammation, which is associated with chlamydial infections, could contribute to the pathogenetic processes that lead to the metabolic and hormonal disorders of PCOS.

Comparison of metabolic and inflammatory outcomes in women who used oral contraceptives and the levonorgestrel-releasing intrauterine device in a general population

We compared the metabolic and cardiovascular parameters of a reference group of women with those of women who used 2 contraceptive regimes that are used worldwide: the levonorgestrel-releasing intrauterine device and oral contraceptives. We investigated a cohort of 2814 women at age 31 years from the general population-based Northern Finland Birth Cohort who were born in 1966. Women were classified as oral contraceptive users (n = 687 women), levonorgestrel-releasing intrauterine device users (n = 168 women), or no use of hormonal contraception (reference group; n = 1959 women). The analyses were adjusted for body mass index, current alcohol use, household income, and area of residence. Compared with the reference group, oral contraceptive users had higher systolic and diastolic blood pressure, raised levels of inflammatory indices (C-reactive protein), and impaired insulin sensitivity. Levonorgestrel-releasing intrauterine device users displayed a lower high-density lipoprotein and total cholesterol, but a similar cholesterol/ high-density lipoprotein ratio, and higher leukocyte count compared with the reference group. Oral contraception users were insulin-resistant compared with levonorgestrel-releasing intrauterine device users with higher blood pressure, raised lipid levels (such as total cholesterol and triglycerides) and insulin levels, and lower homeostasis model assessment and insulin sensitivity, despite smaller waist and lower waist-hip ratio. Oral contraception usage was associated with adverse findings in several metabolic, cardiovascular, and inflammatory parameters, which is consistent with an increased future risk of cardiovascular and metabolic disease. These findings should invite more criticism of recent trends that encourage the prescription of oral contraceptives for years during reproductive life and especially in premenopausal women. In contrast, levonorgestrel-releasing intrauterine device or progestin-only pills may offer long-term health benefits over oral contraceptives and should be preferred to oral contraceptives for women in their forties and/or with metabolic risk factors for cardiovascular diseases and type 2 diabetes mellitus.

Prevalence of metabolic syndrome at age 16 using the International Diabetes Federation paediatric definition

Objective:We estimated the prevalence of metabolic syndrome (MS) in adolescents, using the new International Diabetes Federation (IDF) paediatric definition and compared this with prevalence estimated using the IDF adult definition...

Metabolic cardiovascular disease risk factors in women with self-reported symptoms of oligomenorrhea and/or hirsutism: Northern Finland Birth Cohort 1966 Study.

The metabolic cardiovascular disease (CVD) risk factors of women with self-reported oligomenorrhea and/or hirsutism, which are symptoms of polycystic ovary syndrome (PCOS), were investigated in a general population-based Northern Finland Birth Cohort 1966 Study to determine whether women with PCOS symptoms at 31 yr would be distinguishable from asymptomatic controls in terms of CVD risk factors. A total of 518 cases with oligomenorrhea and/or hirsutism and 1036 randomly selected controls were analyzed. C-Reactive protein (CRP; median, 0.70 vs. 0.60 mg/liter; P = 0.026), triglycerides (mean, 0.97 vs. 0.91 mmol/liter; P = 0.039), body mass index (BMI; mean, 25.1 vs. 24.2 kg/m(2); P < 0.001), and waist/hip ratio (mean, 0.82 vs. 0.81; P = 0.001) were significantly higher, and high-density lipoprotein cholesterol levels were lower (mean, 1.60 vs. 1.66 mmol/liter; P = 0.002) in the cases compared with the controls. Total cholesterol, low-density lipoprotein cholesterol, and blood pressure showed no statistically significant differences between the cases and the controls. In terms of metabolic CVD risk factors, women reporting hirsutism alone were indistinguishable from the control group, and those who reported both oligomenorrhea and hirsutism had the most severe changes in risk factor profiles. Because obesity is strongly related to PCOS symptoms, the analyses were stratified by BMI. After stratification into normal weight (BMI, <25 kg/m(2)), overweight (25 kg/m(2) <or= BMI <30 kg/m(2)), and obese (BMI, >or=30 kg/m(2)) groups, the waist/hip ratio was significantly higher among the overweight cases (mean, 0.84 vs. 0.83; P = 0.04). Among the obese women, high-density lipoprotein cholesterol was significantly lower (mean, 1.32 vs. 1.48 mmol/liter; P = 0.002) among the cases, and triglycerides tended to be higher (mean, 1.43 vs. 1.27 mmol/liter; P = 0.068) than in controls. In conclusion, these results indicate that self-reported symptoms of oligomenorrhea and/or hirsutism, particularly in the presence of both symptoms, may be helpful to identify women with metabolic cardiovascular risk factor accumulation associated with PCOS.

Prevalence of polycystic ovaries in women with self-reported symptoms of oligomenorrhoea and/or hirsutism: Northern Finland Birth Cohort 1966 Study.

The aim of this study was to investigate the prevalence of polycystic ovaries (PCO) among women with self-reported oligomenorrhoea and/or hirsutism and to see whether women with symptoms and PCO have less favourable levels of biochemical markers than controls or women with symptoms and normal ovaries. The ultrasonographic ovarian morphology and the hormonal and metabolic profile of female cases with self-reported symptoms typical of polycystic ovary syndrome (PCOS) (n = 196) and asymptomatic controls (n = 67) at the age of 31 years were examined in a general population-based Northern Finland Birth Cohort 1966. The prevalence of PCO (37.3 versus 18.2%; P = 0.004) was significantly higher in the cases (oligomenorrhoea and/or hirsutism) than in the controls. PCO morphology was detected in 18.4% of those who reported only hirsutism, in 47.9% of those reporting only oligomenorrhoea, and in 70.4% of those reporting both symptoms. In the cases with PCO compared to (i) the controls and (ii) the cases without PCO, body mass index (P = 0.026 and P = 0.011), ovarian volume [right P = 0.001, left P = 0.208 (non-significant) and right P < 0.001, left P = 0.022], mean follicle number (P < 0.001 and P < 0.001), testosterone (P = 0.063 and P = 0.029), free androgen index (P = 0.007 and P = 0.013) and insulin (P = 0.033 and P = 0.040) were higher, and sex hormone-binding globulin (P = 0.039 and P = 0.068) and glucose:insulin ratio (P = 0.060 and P = 0.054) lower. Cases with PCO also had higher waist:hip ratio (P = 0.011), infertility rate (P = 0.005) and glucose (P = 0.045) and lower insulin-like growth factor-binding protein-1 (P = 0.012) than controls. The clinical, hormonal and metabolic characteristics did not differ significantly between cases without PCO and controls with the exception of infertility rate, which was significantly higher in the cases without PCO (26.4 vs. 10.0%; P = 0.009). In a general population, women with symptoms of oligomenorrhoea and/or hirsutism more often have PCO than asymptomatic women. Levels of biochemical and clinical markers in symptomatic women with PCO differed from and were less favourable than those in symptomatic women without PCO or asymptomatic women, implying an increased risk for health.

Hormonal profile of women with self-reported symptoms of oligomenorrhea and/or hirsutism: Northern Finland birth cohort 1966 study.

The hormonal profiles of nested female patients (n = 500) with self-reported symptoms typical of polycystic ovary syndrome (PCOS), oligomenorrhea, and/or hirsutism and their randomly selected controls (n = 1026) at the age of 31 yr were analyzed in a general population-based Northern Finland birth cohort 1966 to find out whether the symptomatic women also have the endocrine characteristics of PCOS and could be detected in a general population using simple questions. Higher medians of serum testosterone (T) (2.10 vs. 1.90 nmol/liter, P < 0.001), LH (5.40 vs. 4.85 U/liter, P = 0.005), insulin (53.8 vs. 51.66 pmol/liter, P = 0.040), and free androgen index (FAI) (4.01 vs. 3.03, P < 0.001) and lower glucose/insulin ratio (91.1 x 10(8) vs. 94.9 x 10(8), P = 0.048) and SHBG (52.4 vs. 60.7 nmol/liter, P < 0.001) were observed among the cases, but no difference was observed in cortisol and glucose levels between the cases and controls. Of all the women in the cohort, 10.2% reported only oligomenorrhea and had biochemical findings similar to the whole case group. Those who reported only hirsutism (10.4%) were in between the case and control groups according to biochemical findings. The subjects who reported both oligomenorrhea and hirsutism (3.4%) had the highest T, LH, FAI, insulin, and glucose and the lowest SHBG and glucose/insulin ratio, compared with the case group and the groups with either symptom only indicating a dose-response manner in typical endocrine profile of PCOS by adding up symptoms. The levels of T and FAI were higher and SHBG lower in groups with overweight or obesity both at 14 and 31 yr, compared with groups with normal weight at 14 yr and overweight or obesity at 31 yr. In the group with normal weight at 14 and 31 yr and the group with overweight or obesity at 14 yr but normal weight at 31 yr, the levels of T and FAI were lowest and SHBG highest. T and FAI were higher and SHBG lower among the cases than the controls in groups stratified by weight development from adolescence to adulthood. In conclusion, this longitudinal study of a large, stable population indicates that women with self-reported symptoms of hirsutism and/or oligomenorrhea show endocrine characteristics of PCOS and can be detected in a general population using simple questions. These symptoms are markers of the underlying metabolic alterations possibly associated with increased health risks in later life.