O-163 Hyperandrogenaemia in early adulthood is an independent risk factor for abnormal glucose metabolism in later life

Study question

What is the role of androgen excess as a contributing factor to insulin resistance and abnormal glucose metabolism (AGM) in women?

Summary answer

There was a positive association between early adulthood hyperandrogenaemia with AGM. Serum SHBG levels could help identifying women at risk for disordered glucose metabolism.

What is known already

It is commonly recognised that insulin resistance induces compensatory hyperinsulinaemia which promotes ovarian androgen secretion. Studies in rodents have also suggested that testosterone causes prolonged activation of androgen receptor in pancreatic islet β-cells, inducing insulin hypersecretion and eventually secondary β-cell failure, thus predisposing to type 2 diabetes (T2D). However, the exact physiology behind the association between androgens, insulin resistance and T2D in women is not well understood. Many previously published studies are limited by cross-sectional study design, unrepresentative clinic populations, as well as variying steroid hormone measurement methods and definitions of androgen excess.

Study design, size, duration

A prospective longitudinal population-based cohort (n = 5,889) to investigate whether serum levels of testosterone (T, measured using LC-MS/MS) and free androgen index (FAI) at ages 31 and 46 associated with AGM at age 46 years. After exclusion of pregnant women, users of hormonal intrauterine device, contraceptive pills, hormone therapy, minipills and statins, there were 4,421 women at age 31 and 4,457 women at age 46. At age 46 a two-hour OGTT was performed in 2,780 women.

Participants/materials, setting, methods

Serum fasting glucose and insulin, insulin resistance (HOMA–IR) and pancreatic β-cell function (HOMA–B) assessments were performed at ages 31 and 46. Elevated T levels (age 31: >2.3nmol/l; age 46: >1.7nmol/l) were defined according to the 97.5% percentile. T2D diagnoses were gathered from postal questionnaire at age 46, and verified and completed from the hospital discharge and national medication reimbursement registers. Impaired fasting glucose, impaired glucose tolerance or T2D were categorised as AGM.

Main results and the role of chance

At age 31, hyperandrogenic (HA) women displayed increased insulin resistance estimated by HOMA-IR (1.35±0.96 vs. 1.03±0.44, P = 0.05), increased insulin secretion estimated by HOMA-B (115.05±34.67 vs. 99.25±25.47, P = 0.006), and higher fasting insulin level (10.48±7.54 mU/l vs. 7.93±3.42 mU/l, P = 0.034) compared with normoandrogenic (NA) women, after BMI adjustment. At age 46, HA women had comparable HOMA-B levels (98.04±60.03 vs. 96.27±65.89, P = 0.93) but their fasting glucose (5.57±1.06 mmol/l vs. 5.37±0.77 mmol/, P = 0.07) and glycated haemoglobin levels (37.47±7.83 mmol/mol vs. 36.18±4.99 mmol/mol, P = 0.07) tended to be higher.

Women in the highest T quartile (Q4

odds ratio [OR]=1.77, 95%CI: [1.14–2.76]) and in the two highest FAI quartiles at age 31 (Q4: OR = 3.61 [2.16–6.03] and Q3: OR = 2.11 [1.24–3.59]) had increased risk for AGM at age 46, independently of BMI, when compared with women in the lowest quartile. Similarly, women in the two highest FAI quartiles at age 46 had increased risk for AGM (Q4: OR = 2.91 [1.82–4.64]) when compared with women in the lowest quartile, after BMI adjustment. The three highest sex hormone-binding globulin (SHBG) quartiles inversely associated with AGM, both at ages 31 and 46, independently of BMI (at age 31: Q4: OR = 0.38 [0.24–0.62], at age 46: Q4: OR = 0.27 [0.17–0.44]).

Limitations, reasons for caution

We used only serum T as a marker of HA, even though other androgens, such as androstenedione and adrenal androgens have a place in the evaluation of androgenicity in women. Further studies of other large populations are needed to confirm our results.

Wider implications of the findings

This is the first longitudinal, general population based study to confirm a positive association between early adulthood hyperandrogenaemia with AGM in middle adulthood independently of confounding factors. Our results further suggest that SHBG levels could help to identify women at risk for AGM.

Trial registration number

NA

Genome-wide association and epidemiological analyses reveal common genetic origins between uterine leiomyomata and endometriosis

Uterine leiomyomata (UL) are the most common neoplasms of the female reproductive tract and primary cause for hysterectomy, leading to considerable morbidity and high economic burden. Here we conduct a GWAS meta-analysis in 35,474 cases and 267,505 female controls of European ancestry, identifying eight novel genome-wide significant (P < 5 × 10^-8) loci, in addition to confirming 21 previously reported loci, including multiple independent signals at 10 loci. Phenotypic stratification of UL by heavy menstrual bleeding in 3409 cases and 199,171 female controls reveals genome-wide significant associations at three of the 29 UL loci: 5p15.33 (TERT), 5q35.2 (FGFR4) and 11q22.3 (ATM). Four loci identified in the meta-analysis are also associated with endometriosis risk; an epidemiological meta-analysis across 402,868 women suggests at least a doubling of risk for UL diagnosis among those with a history of endometriosis. These findings increase our understanding of genetic contribution and biology underlying UL development, and suggest overlapping genetic origins with endometriosis.

Metabolic profiling of polycystic ovary syndrome reveals interactions with abdominal obesity

Background:

Polycystic ovary syndrome (PCOS) is a common reproductive disorder associated with metabolic disturbances including obesity, insulin resistance and diabetes mellitus. Here we investigate whether changes in the metabolic profile of PCOS women are driven by increased tendency to obesity or are specific features of PCOS related to increased testosterone levels.

Design and methods:

We conducted an NMR metabolomics association study of PCOS cases (n=145) and controls (n=687) nested in a population-based birth cohort (n=3127). Subjects were 31 years old at examination. The main analyses were adjusted for waist circumference (WC) as a proxy measure of central obesity. Subsequently, metabolite concentrations were compared between cases and controls within pre-defined WC strata. In each stratum, additional metabolomics association analyses with testosterone levels were conducted separately among cases and controls.

Results:

Overall, women with PCOS showed more adverse metabolite profiles than the controls. Four lipid fractions in different subclasses of very low density lipoprotein (VLDL) were associated with PCOS, after adjusting for WC and correction for multiple testing (P<0.002). In stratified analysis the PCOS women within large WC strata (⩾98 cm) had significantly lower high density lipoprotein (HDL) levels, Apo A1 and albumin values compared with the controls. Testosterone levels were significantly associated with VLDL and serum lipids in PCOS cases with large WC but not in the controls. The higher testosterone levels, adjusted for WC, associated adversely with insulin levels and HOMA IR in cases but not in the controls.

Conclusions:

Our findings show that both abdominal obesity and hyperandrogenism contribute to the dyslipidaemia and other metabolic traits of PCOS which all may negatively contribute to the long-term health of women with PCOS.

Overweight and obese but not normal weight women with PCOS are at increased risk of Type 2 diabetes mellitus-a prospective, population-based cohort study

STUDY QUESTION

What are the respective roles of polycystic ovary syndrome (PCOS), long-term weight gain and obesity for the development of prediabetes or Type 2 diabetes mellitus (T2DM) by age 46 years?

SUMMARY ANSWER

The risk of T2DM in women with PCOS is mainly due to overweight and obesity, although these two factors have a synergistic effect on the development of T2DM.

WHAT IS KNOWN ALREADY

PCOS is associated with an increased risk of prediabetes and T2DM. However, the respective roles of PCOS per se and BMI for the development of T2DM have remained unclear.

STUDY DESIGN, SIZE, DURATION

In a prospective, general population-based follow-up birth cohort 1966 (n = 5889), postal questionnaires were sent at ages 14 (95% answered), 31 (80% answered) and 46 years (72% answered). Questions about oligoamenorrhoea and hirsutism were asked at age 31 years, and a question about PCOS diagnosis at 46 years. Clinical examination and blood sampling were performed at 31 years in 3127 women, and at 46 years in 3280 women. A 2-h oral glucose tolerance test (OGTT) was performed at 46 years of age in 2780 women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women reporting both oligoamenorrhoea and hirsutism at age 31 years and/or diagnosis of PCOS by 46 years were considered as women with PCOS (n = 279). Women without any symptoms at 31 years and without PCOS diagnosis by 46 years were considered as controls (n = 1577). The level of glucose metabolism was classified according to the results of the OGTT and previous information of glucose metabolism status from the national drug and hospital discharge registers.

MAIN RESULTS AND THE ROLE OF CHANCE

PCOS per se significantly increased the risk of T2DM in overweight/obese (BMI ≥ 25.0 kg/m²) women with PCOS when compared to overweight/obese controls (odds ratio: 2.45, 95% CI: 1.28-4.67). Normal weight women with PCOS did not present with an increased risk of prediabetes or T2DM. The increase in weight between ages 14, 31 and 46 years was significantly greater in women with PCOS developing T2DM than in women with PCOS and normal glucose tolerance, with the most significant increase occurring in early adulthood (between 14 and 31 years: median with [25%; 75% quartiles]: 27.25 kg [20.43; 34.78] versus 13.80 kg [8.55; 20.20], P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

The diagnosis of PCOS was based on self-reporting, and the questionnaire at 46 years did not distinguish between polycystic ovaries only in ultrasonography and the syndrome. Ovarian ultrasonography was not available to aid the diagnosis of PCOS.

WIDER IMPLICATIONS OF THE FINDINGS

These results emphasize weight management already during adolescence and early adulthood to prevent the development of T2DM in women with PCOS, as the period between 14 and 31 years seems to be a crucial time-window during which the women with PCOS who are destined to develop T2DM by 46 years of age experience a dramatic weight gain. Furthermore, our results support the view that, particularly in times of limited sources of healthcare systems, OGTT screening should be targeted to overweight/obese women with PCOS rather than to all women with PCOS.

STUDY FUNDING/COMPETING INTERESTS

Finnish Medical Foundation; North Ostrobothnia Regional Fund; Academy of Finland (project grants 104781, 120315, 129269, 1114194, 24300796, Center of Excellence in Complex Disease Genetics and SALVE); Sigrid Juselius Foundation; Biocenter Oulu; University Hospital Oulu and University of Oulu (75617); Medical Research Center Oulu; National Institute for Health Research (UK); National Heart, Lung, and Blood Institute (grant 5R01HL087679-02) through the STAMPEED program (1RL1MH083268-01); National Institute of Health/National Institute of Mental Health (5R01MH63706:02); ENGAGE project and grant agreement HEALTH-F4-2007-201413; EU FP7 EurHEALTHAgeing-277849 European Commission and Medical Research Council, UK (G0500539, G0600705, G1002319, PrevMetSyn/SALVE) and Medical Research Center, Centenary Early Career Award. The authors have no conflicts of interests.

TRIAL REGISTRATION NUMBER

N/A.

Association between occupational psychosocial factors and waist circumference is modified by diet among men

BACKGROUND/OBJECTIVES

Occupational psychosocial stress has been identified as a risk factor for obesity, whereas dietary habits have a key role in weight control. We examined whether dietary habits modify the association between occupational psychosocial factors and waist circumference.

SUBJECTS/METHODS

Data comprised 31-year-old men (n=2222) and women (n=2053) in the Northern Finland Birth Cohort 1966. Waist circumference was measured and data on occupational psychosocial factors (demands, control and social support) and other characteristics were obtained through questionnaires. Healthy and unhealthy diet indices were constructed according to the current dietary guidelines. Associations were examined using analysis of variance adjusted for body mass index at age 14, basic education level, leisure-time physical activity, alcohol consumption, smoking, stress-related eating behaviour and parity.

RESULTS

Among men, high job demands and high job control were associated with greater waist circumferences, and there were interactions between unhealthy diet and job demands (P=0.043) and job control (P=0.036) in relation to waist circumference. The waist of men with high demands or high control and low consumption of unhealthy foods (red/processed meat, hamburgers and pizzas, fried potatoes, sugar-sweetened soft drinks and white bread) was smaller than that of men with high demands or high control and high consumption of such foods. No associations were found among women.

CONCLUSIONS

A diet based on the current dietary guidelines seems to cancel out the adverse effects of occupational psychosocial factors on waist circumference among young men. Longitudinal studies are needed to assess the risks for obesity-related diseases arising from psychosocial work environments and dietary habits.

Irregular menstruation and hyperandrogenaemia in adolescence are associated with polycystic ovary syndrome and infertility in later life: Northern Finland Birth Cohort 1986 study

STUDY QUESTION

Do teenage girls with a history of menstrual irregularity and/or elevated androgen levels in adolescence exhibit an increased risk of polycystic ovary syndrome (PCOS) and/or infertility later on in adulthood?

SUMMARY ANSWER

Our results suggest that menstrual irregularity and/or elevated androgen levels at 16 years are still associated with symptoms of PCOS at 26 years as well as infertility problems at 26 years but not with decreased pregnancy or delivery rates at 26 years.

WHAT IS KNOWN ALREADY

Hyperandrogenaemia is associated with menstrual irregularity, hirsutism, acne and potentially higher risk for PCOS, but there are few follow-up studies investigating whether adolescent hyperandrogenaemia and/or menstrual irregularity are an early sign of PCOS.

STUDY DESIGN, SIZE, DURATION

A prospective population-based cohort study was conducted using two postal questionnaires targeting girls in the Northern Finland Birth Cohort 1986 (NFBC1986, n = 4567). The NFBC1986 comprises all expected births from the year 1986 in the two northernmost provinces of Finland. Collection of the database was performed at the age of 16 and 26. The 16-year and 26-year questionnaires included one question about the regularity and length of the menstrual cycle. The 26-year questionnaire also included questions about symptoms of PCOS, reproduction and infertility problems.

PARTICIPANTS, SETTING, METHODS

The response rates for the questionnaires were 80% (n = 3669) at 16 years and 50% (n = 2270) at 26 years. At 15-16 years, of 2448 girls, 709 (29%) girls reported menstrual irregularity (symptomatic girls) and 1739 (71%) had regular periods (non-symptomatic girls). After combining data from the two questionnaires a total of 2033 girls were included in the analyses. The χ(2) and Student's t-test was used to compare reproductive outcome and prevalence of clinical hyperandrogenaemia, PCOS and infertility at 26 years between the study groups. Univariate and multivariate logistic regression models were employed to estimate the association of menstrual irregularity at 16 years with clinical hyperandrogenaemia, PCOS and infertility at 26 years.

MAIN RESULTS AND THE ROLE OF CHANCE

At follow-up, the proportion of symptomatic girls who had conceived at least once (68.0 versus 67.9%) and had delivered at least one child (25.7 versus 28.1%) was similar to the non-symptomatic women and the groups had similar miscarriage rates (11.6 versus 12.1%). Logistic regression analyses indicated that menstrual irregularity at 16 years was associated with an increased risk of menstrual irregularity [adjusted odds ratio (OR) 1.37, 95% confidence interval (CI) 1.00-1.88, P = 0.050], PCOS (adjusted OR 2.91, 95% CI 1.74-4.84, P < 0.001) and infertility problems (adjusted OR 2.07, 95% CI 1.16-3.76, P = 0.013) at 26 years. At 26 years, women with PCOS (P = 0.013), hirsutism (P = 0.001) and acne (P < 0.001) exhibited significantly higher values of free androgen index (FAI) at 16 years than control women. There was a significant linear trend in the higher FAI quartiles at 16 years towards higher prevalence of PCOS (P = 0.005), hirsutism (P < 0.001) and acne (P < 0.001) at 26 years. Only 10.5% of the girls with menstrual irregularity at 16 years had PCOS at 26 years.

LIMITATIONS, REASONS FOR CAUTION

The diagnosis of menstrual irregularity was based on a self-reported questionnaire, thus introducing a risk of information bias in reporting the symptoms. Moreover, ovarian ultrasonography was not available to aid the diagnosis of PCOS and there was no clinical evaluation of hyperandrogenism. The relatively low rate of participation to the questionnaire at 26 years may also have biased the results.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings confirm that menstrual irregularity and/or elevated androgen levels are already present in adolescence in women with PCOS and infertility in later life, which strengthens the importance of early identification of menstrual irregularity.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the Finnish Medical Society Duodecim, the North Ostrobothnia Regional Fund, the Academy of Finland, the Sigrid Juselius Foundation, University Hospital Oulu and University of Oulu, the European Commission and the Medical Research Council, UK, Welcome Trust (089549/Z/09/Z). None of the authors have any conflict of interest.

Anti-Müllerian hormone: correlation with testosterone and oligo- or amenorrhoea in female adolescence in a population-based cohort study

STUDY QUESTIONS

Can serum anti-Müllerian hormone (AMH) levels measured in female adolescents predict polycystic ovary syndrome (PCOS)-associated features in adolescence and early adulthood?

SUMMARY ANSWER

AMH levels associated well with PCOS-associated features (such as testosterone levels and oligoamenorrhoea) in adolescence, but was not an ideal marker to predict PCOS-associated features in early adulthood.

WHAT IS KNOWN ALREADY

Several studies have reported that there is a strong correlation between antral follicle count and serum AMH levels and that women with PCOS/PCO have significantly higher serum AMH levels than women with normal ovaries. Other studies have reported an association between AMH serum levels and hyperandrogenism in adolescence, but none has prospectively assessed AMH as a risk predictor for developing features of PCOS during adulthood.

STUDY DESIGN, SIZE, DURATION

A subset of 400 girls was selected from the prospective population-based Northern Finland Birth Cohort 1986 (n = 4567 at age 16 and n = 4503 at age 26). The population has been followed from 1986 to the present.

PARTICIPANTS/MATERIAL, SETTING, METHODS

At age 16, 400 girls (100 from each testosterone quartile: 50 with oligo- or amenorrhoea and 50 with a normal menstrual cycle) were selected at random from the cohort for AMH measurement. Metabolic parameters were also assessed at age 16 in all participants. Postal questionnaires enquired about oligo- or amenorrhoea, hirsutism, contraceptive use and reproductive health at ages 16 and 26.

MAIN RESULTS AND ROLE OF CHANCE

There was a significant correlation between AMH and testosterone at age 16 (r = 0.36, P < 0.001). AMH levels at age 16 were significantly higher among girls with oligo- or amenorrhoea compared with girls with normal menstrual cycles (35.9 pmol/l [95% CI: 33.2;38.6] versus 27.7 pmol/l [95% CI: 25.0;30.4], P < 0.001). AMH at age 16 was higher in girls who developed hirsutism at age 26 compared with the non-hirsute group (31.4 pmol/l [95% CI 27.1;36.5] versus 25.8 pmol/l [95% CI 23.3;28.6], P = 0.036). AMH at age 16 was also higher in women with PCOS at age 26 compared with the non-PCOS subjects (38.1 pmol/l [95% CI 29.1;48.4] versus 30.2 pmol/l [95% CI 27.9;32.4], P = 0.044). The sensitivity and specificity of the AMH (cut-off 22.5 pmol/l) for predicting PCOS at age 26 was 85.7 and 37.5%, respectively. The addition of testosterone did not significantly improve the accuracy of the test. There was no significant correlation between AMH levels and metabolic indices at age 16.

IMPLICATIONS, REASONS FOR CAUTION

AMH is related to oligo- or amenorrhoea in adolescence, but it is not a good marker for metabolic factors. The relatively low rate of participation in the questionnaire at age 26 may also have affected the results. AMH was measured in a subset of the whole cohort. AMH measurement is lacking international standardization and therefore the concentrations and cut-off points are method dependent.

WIDER IMPLICATIONS FOR THE FINDINGS

Using a high enough cut-off value of AMH to predict which adolescents are likely to develop PCOS in adulthood could help to manage the condition from an early age due to a good sensitivity. However, because of its low specificity, it is not an ideal diagnostic marker, and its routine use in clinical practice cannot, at present, be recommended.

STUDY FUNDINGS AND COMPETING INTERESTS

The study was funded by a grant from Wellcome Trust (089549/Z/09/Z) to H.L., S.F. and M.-R.J. Study funding was also received from Oulu University Hospital Research Funds, Sigrid Juselius Foundation and the Academy of Finland. None of the authors have any competing interest to declare.

Serum sex hormone-binding globulin and testosterone in relation to cardiovascular disease risk factors in young men: a population-based study

OBJECTIVE

Reduced sex hormone-binding globulin (SHBG) concentration predicts insulin resistance and type 2 diabetes, but its association with cardiovascular disease (CVD) risk is unclear. We examined the association between SHBG and cardiovascular risk factors, independently of total testosterone (TT), in young men.

DESIGN

Observational, cross-sectional study.

SETTING

General community.

PARTICIPANTS

The study included 2716 men aged 31 years in the Northern Finland Birth Cohort in 1996 with clinical examination data and fasting blood samples.

OUTCOME VARIABLES

Blood pressure (BP), lipids and C-reactive protein (CRP) as biological CVD risk markers.

RESULTS

SHBG concentration was significantly and inversely related to systolic and diastolic BP, triglycerides and CRP, but positively to HDL cholesterol after adjusting for insulin, BMI, waist circumference, smoking, education and physical activity (all P<0.05). These linearly graded associations persisted with additional adjustment for TT. SHBG was significantly associated with total cholesterol only with adjustment for covariates and TT (P<0.05). The direction and magnitude of associations between TT and risk factors were variable, but further adjustment for insulin, adiposity and SHBG showed positive associations between TT and BP, total and LDL-cholesterol and triglycerides and an inverse association with CRP (all P<0.05), but its relation with HDL-cholesterol was no longer significant.

CONCLUSIONS

In this cohort of young adult men, higher SHBG concentration was associated with a more favourable CVD risk profile, independently of TT. SHBG concentration modified the associations of TT with CVD risk factors.

Longitudinal associations between childhood and adulthood externalizing and internalizing psychopathology and adolescent substance use

BACKGROUND

Emotional and behavioral problems are commonly associated with substance use in adolescence but it is unclear whether substance use precedes or follows mental health problems. The aim was to investigate longitudinal associations between externalizing and internalizing psychopathology and substance use in a prospective population study design.

METHOD

The sample was the Northern Finland Birth Cohort 1986 Study (NFBC 1986; n = 6349; 3103 males). Externalizing and internalizing mental health problems were assessed at age 8 years (Rutter scales), substance use and externalizing and internalizing problems [Youth Self-Report (YSR)] at age 15-16 years, and hospital diagnoses for internalizing disorders (age 25) and criminal offences (age 20) from nationwide registers in adulthood.

RESULTS

Externalizing problems at age 8 were associated with later substance use. After adjustment for sociodemographic factors, parental alcohol use and psychiatric disorders, and earlier externalizing and internalizing problems, substance use predicted criminality, especially among males, with the highest odds ratio (OR) for cannabis use [adjusted OR 6.2, 95% confidence interval (CI) 3.1-12.7]. Early internalizing problems were not a risk for later substance use. Female adolescent cannabis (OR 3.2, 95% CI 1.4-7.3) and alcohol (OR 2.1, 95% CI 1.1-4.2) use predicted internalizing disorders in adulthood.

CONCLUSIONS

Externalizing problems precede adolescent substance use in both genders, whereas, among boys, substance use also precedes criminal offences. Internalizing problems may follow substance use in females. These associations were robust even when taking into account previous mental health problems.

The impact of self-reported oligo-amenorrhea and hirsutism on fertility and lifetime reproductive success: results from the Northern Finland Birth Cohort 1966

STUDY QUESTION

To what extent do self-reported oligo-amenorrhea and hirsutism affect reproductive performance (childlessness, age at first delivery, family size and miscarriage rates)?

SUMMARY ANSWER

At the age of 44, among women with both self-reported oligo-amenorrhea and hirsutism the prevalence of childlessness was not significantly different from non-symptomatic women but they had a smaller family size than non-symptomatic women.

WHAT IS KNOWN ALREADY

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by oligo-amenorrhea or amenorrhea, hyperandrogenism and hirsutism and it is the most frequent cause of anovulatory infertility, but there are few studies on the reproductive capacity of women with PCOS. In our previous population-based cohort study the women with self-reported oligo-amenorrhea and hirsutism were found to have more infertility problems and smaller family size than non-symptomatic women at the age of 31.

STUDY DESIGN, SIZE, DURATION

A prospective population-based cohort study. The population of the study is derived from the prospective Northern Finland Birth Cohort 1966 (NFBC1966), comprising all expected births from the year 1966 in the two northernmost provinces of Finland (n = 12 058). Of them, 5889 were females. Enrollment in this database begun at the 24th gestational week and so far data have been collected from the subjects at the ages of 1, 14 and 31 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A postal questionnaire including questions about oligo-amenorrhea and hirsutism was sent to all women at the age of 31 (n = 5608, response rate 81%, n = 4535) and a clinical examination was performed (attendance rate 76.5%). Those who reported both hirsutism and oligo-amenorrhea were defined as women with both symptoms (n = 153). Data on pregnancies/deliveries were obtained from the Finnish Medical Birth Register (FMBR) in 2010 when the women were 44 years old.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with both symptoms had delivered at least one child as often as non-symptomatic women [75.2 versus 79.0%, adjusted odds ratio (OR) 0.86, 95% confidence intervals (CI) 0.57-1.30], were of similar age [mean (SD)] at first delivery [27.7 (4.81) versus 27.3 (4.71)] and had similar incidence of miscarriages. However, non-symptomatic women had more often ≥2 deliveries (61.6 versus 52.9%, adjusted OR 0.70, 95% CI 0.49-1.00, P = 0.048) and had larger family size [mean (SD)] [2.4 (1.4) versus 1.9 (0.8), P < 0.001]. Women with both symptoms had been treated more often for infertility than non-symptomatic women (6.1 versus 2.4%, adjusted OR 2.74, 95% CI 1.14-6.60, P = 0.024).

LIMITATIONS, REASONS FOR CAUTION

The diagnosis of oligo-amenorrhea and hirsutism was based on a questionnaire, suggesting a risk of information bias in reporting the symptoms. However, we have previously shown that self-reported oligo-amenorrhea and hirsutism can distinguish most women with the typical profile of PCOS. Only the women who had delivered at least once were recorded in the FMBR, thus excluding from the study those who had experienced miscarriages and/or infertility treatments but did not have a live birth. This feature could potentially decrease the differences in incidence of miscarriages and/or infertility treatment between symptomatic and non-symptomatic subjects.

WIDER IMPLICATIONS OF THE FINDINGS

This is one of the few studies, in which the impact of self-reported oligo-amenorrhea and hirsutism on lifetime reproductive success can be measured. Our results suggest that even at more advanced age, women with both symptoms do not quite match the parity of healthy non-symptomatic women, and that infertility treatment does not always restore normal reproductive capacity in these women. Obese women with both symptoms had the worst prognostic as regards reproduction, which emphasizes the importance of life intervention and preventive politics against obesity in this group of women.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from the Finnish Medical Society Duodecim, the North Ostrobothnia Regional Fund, the Academy of Finland, University Hospital Oulu, Biocenter, University of Oulu, Finland, the European Commission and the Medical Research Council, UK, the National Institute for Health Research (NIHR). None of the authors has any conflict of interest to declare.

Associations of meal frequency and breakfast with obesity and metabolic syndrome traits in adolescents of Northern Finland Birth Cohort 1986

BACKGROUND AND AIMS

Breakfast consumption and meal frequencies have been linked to the risk of obesity in youth but their associations with metabolic syndrome (MetS) in young populations are yet to be studied. We examined associations of three meal patterns on weekdays--five meals including breakfast, ≤four meals including breakfast and ≤four meals without breakfast--with overweight/obesity and MetS components in Finnish adolescents.

METHODS AND RESULTS

A population-based sample of 16-year-old boys and girls (n = 6247) from the Northern Finland Birth Cohort 1986 was used. Adolescents were clinically examined and dietary data were collected using self-administered questionnaires. Overweight/obesity and MetS features were defined according to the International Obesity Task Force cut-offs and the International Diabetes Federation MetS paediatric criteria and their associations with meal patterns assessed using logistic regression, adjusted separately for early life factors (birth size, maternal health) and later childhood factors (health behaviours, weight status, parental education). After adjustment for early life factors, the adolescents who ate five meals/day were at lower risk for overweight/obesity (OR [95% CI] for boys: 0.47 [0.34, 0.65]; girls: 0.57 [0.41, 0.79]), abdominal obesity (OR [95% CI] for boys: 0.32 [0.22, 0.48]; girls: 0.54 [0.39, 0.75]) and hypertriglyceridaemia (boys only). Adjusting for later childhood factors, the five-meal-a-day pattern was associated with decreased odds of overweight/obesity (OR [95% CI] for boys: 0.41 [0.29, 0.58]; girls: 0.63 [0.45, 0.89]) and abdominal obesity in boys (OR 0.32, 95% CI 0.16, 0.63).

CONCLUSION

Among 16-year-olds, the five-meal-a-day pattern was robustly associated with reduced risks of overweight/obesity in both genders and abdominal obesity in boys.

How do changes in body mass index in infancy and childhood associate with cardiometabolic profile in adulthood? Findings from the Northern Finland Birth Cohort 1966 Study

BACKGROUND/OBJECTIVE

Postnatal growth patterns leading to obesity may have adverse influences on future cardiometabolic health. This study evaluated age and body mass index (BMI) at infant BMI peak (BMIP) and childhood BMI rebound (BMIR) in relation to adult cardiometabolic outcomes in the Northern Finland Birth Cohort 1966.

METHODS

BMI at various ages was calculated from frequent height and weight measurements obtained from child health and welfare clinical records. Age and BMI at BMIP and BMIR were derived from random effect models fitted at >0-1.5 years (N=3 265) and >1.5-13 years (N=4 121). Cardiometabolic outcomes were obtained from a clinical examination at age 31 years. Multiple regression models were used to analyse associations between the derived growth parameters and cardiometabolic outcomes.

RESULTS

Age and BMI at BMIP were positively associated with adult BMI and waist circumference (WC), independently of birth weight and infant height growth (P<0.05). Later BMIR was associated with a better cardiometabolic profile: adult BMI and insulin were 14% lower, WC and triglycerides were 10% lower and the odds of metabolic syndrome (MetS) were 74% lower per 2 s.d. (1.86 years) higher age at BMIR (P<0.0001). BMI at rebound had generally weaker associations with cardiometabolic outcomes, which attenuated after adjustment for age at BMIR.

CONCLUSIONS

Age and BMI at infant BMIP were associated with adult adiposity but not with other cardiometabolic outcomes. Earlier timing of BMIR was a risk factor of an adverse cardiometabolic profile, independently of early growth or BMI at rebound. Identifying growth patterns harmful to cardiovascular health will give opportunities for early interventions.

Geographical distribution of dental caries prevalence and associated factors in young adults in Finland

Oral health of the young has been reported to be associated with the place of residence, due to differences in socio-economic status. The results of studies on the effect of fluoride in drinking water on caries prevalence have been contradictory. The main aim of our study was to investigate the geographical distribution of dental caries prevalence in Finland and analyse possible regional, associated factors. Oral health of 13,564 men born between 1990 and 1992 was screened using a method based on criteria of the World Health Organization for epidemiological studies by 15 calibrated dentists in 20/24 garrisons of the Finnish Defence Forces in 2011. Mean DMFT and DT values in provinces were calculated. Multilevel analysis was applied to the data using generalized linear mixed models and a logit link function. The binary outcome variable was the cariological treatment need (yes/no) and the garrison was treated as random effect. Mean DMFT and DT values varied significantly between provinces in Finland. Increased levels of fluoride in drinking water, Swedish as the main language in the municipality, and living in urban areas were protective factors against cariological treatment need. Dentist density did not affect caries prevalence. The geographical distribution of dental caries further supported estimates of the protective effects of high fluoride levels in drinking water, Swedish as the main language in the municipality, as well as living in urban areas. Effect of fluoride on caries prevalence still exists, and association with the socio-economic status was confirmed.

Menstrual disorders in adolescence: a marker for hyperandrogenaemia and increased metabolic risks in later life? Finnish general population-based birth cohort study

STUDY QUESTION

Are self-reported menstrual disorders associated with hyperandrogenaemia and metabolic disturbances as early as in adolescence?

SUMMARY ANSWER

Menstrual disorders at the age 16 are a good marker of hyperandrogenaemia, and an adverse lipid profile was associated with higher androgen levels.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

Hyperandrogenism per se has been suggested to be a significant metabolic risk factor in women and a cause of physical and psychological morbidity in adolescent girls. A weak positive correlation has been described between hyperandrogenaemia and obesity in adolescent girls, but the clinical consequences are still poorly understood. Hyperandrogenism and insulin resistance are also key features of polycystic ovary syndrome (PCOS), and women with PCOS are consequently at an increased risk of developing type 2 diabetes mellitus and/or metabolic syndrome, and may have increased cardiovascular morbidity. Our findings confirm that the association between menstrual disorders, hyperandrogenism, obesity and metabolic risks is already evident in adolescence.

STUDY DESIGN

This population-based, cross-sectional study used postal questionnaires to targeting 15-16-year-old girls in the Northern Finland Birth Cohort 1986 (n= 4567).

PARTICIPANTS AND SETTING

There were 3669 girls who answered the postal questionnaire and out of 3373 girls who also underwent clinical examinations and blood tests, 2448 were included in the analyses. The questionnaire included one question about the regularity and length of the menstrual cycle: 'Is your menstrual cycle (the interval from the beginning of one menstrual period to the beginning of the next period) often (more than twice a year) longer than 35 days?' The girls who answered 'yes' to this question were considered to be suffering from menstrual disorders and were classified as 'symptomatic'. The girls who answered 'no' were defined as 'non-symptomatic'.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 709 (29%) girls who reported menstrual disorders (symptomatic girls) and 1739 who had regular periods (non-symptomatic girls). In the whole population and in both study groups, there were significant correlations between body mass index (BMI) (and waist-to-hip ratio), hyperandrogenaemia and metabolic parameters. Symptomatic girls exhibited significantly higher serum concentrations of testosterone (P= 0.010), lower levels of sex hormone-binding globulin (P =0.042) and higher free androgen indices [FAIs; geometric mean 3.38 (interquartile range (IQR): 2.27, 5.18) versus 3.08 (IQR: 2.15, 4.74), P= 0.002]. The two groups had comparable BMI and insulin sensitivity, and serum levels of glucose, insulin and lipids. There was a significant linear trend towards higher FAI values in the higher BMI quartiles in both symptomatic and non-symptomatic girls. In the whole population, there was a statistically significant linear decrease in high-density lipoprotein concentrations (P < 0.001) and higher triglyceride concentrations (P =0.004) in the upper FAI quartile.

IMPLICATIONS

Information regarding menstrual disorders in adolescence is a good marker of hyperandrogenaemia and may be an early risk factor for the development of PCOS in adulthood. The association between obesity, hyperandrogenism and metabolic risks is already evident in adolescence, which strengthens the importance of noting menstrual disorders at an early stage. BIAS, LIMITATIONS, GENERALIZABILITY: The cross-sectional nature of the study does not allow us to draw conclusions concerning the metabolic risks of this population in later life. The diagnosis of menstrual disorders was based on a questionnaire, suggesting a risk of information bias in reporting the symptoms. This study was not designed to diagnose PCOS, as ultrasonography was not available and there was no clinical evaluation of hyperandrogenism (i.e. hirsutism). However, we were able to take into account potential confounding factors in the analyses.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the Finnish Medical Society Duodecim, the North Ostrobothnia Regional Fund, the Academy of Finland (project grants 104781, 120315, 129269, 1114194, SALVE), University Hospital Oulu, Biocenter, University of Oulu, Finland (75617), the European Commission (EURO-BLCS, Framework 5 award QLG1-CT-2000-01643) and the Medical Research Council, UK (PrevMetSyn/SALVE). None of the authors have any conflict of interest to declare.

Maternal weight gain during the first half of pregnancy and offspring obesity at 16 years: a prospective cohort study

OBJECTIVE

To assess the association between maternal gestational weight gain (GWG) during the first 20 weeks of gestation and overweight/obesity and abdominal obesity of offspring at the age of 16 years.

DESIGN

A prospective cohort study.

SETTING

The two northernmost provinces of Finland.

POPULATION

Mothers and their adolescent offspring born from singleton pregnancies (3265 boys; 3372 girls) in the Northern Finland Birth Cohort 1986.

METHODS

Maternal weight at 20 weeks of gestation was measured in municipal maternity clinics. Maternal GWG was based on the difference between the measured weight and self-reported pre-pregnancy weight, and was classified into quartiles. Offspring weight, height and waist circumference were measured by study nurses during a clinical examination. Logistic regression analyses [with and without adjustment for maternal pre-pregnancy body mass index (BMI), glucose metabolism, education level, haemoglobin, smoking status, parity, and gender of offspring] were performed.

MAIN OUTCOME MEASURE

Offspring overweight/obesity, based on BMI and abdominal obesity at 16 years.

RESULTS

The highest quartile of maternal weight gain (>7.0 kg during the first 20 weeks of gestation) was independently associated with BMI-based overweight/obesity and abdominal obesity in the 16-year-old offspring (OR 1.46, 95% CI 1.16-1.83, and OR 1.37, 95% CI 1.10-1.72, respectively). Among all covariates, maternal pregravid obesity showed the highest odds for both overweight/obesity and abdominal obesity (OR 4.57, 95% CI 3.18-6.57, and OR 4.43, 95% CI 3.10-6.34, respectively).

CONCLUSIONS

Maternal overnutrition during the first half of gestation predicts offspring overweight/obesity and abdominal obesity in adolescence, yet a high pregravid BMI appears to be a more important determinant of both outcomes.

A genome-wide meta-analysis of association studies of Cloninger's Temperament Scales

Temperament has a strongly heritable component, yet multiple independent genome-wide studies have failed to identify significant genetic associations. We have assembled the largest sample to date of persons with genome-wide genotype data, who have been assessed with Cloninger's Temperament and Character Inventory. Sum scores for novelty seeking, harm avoidance, reward dependence and persistence have been measured in over 11,000 persons collected in four different cohorts. Our study had >80% power to identify genome-wide significant loci (P<1.25 × 10(-8), with correction for testing four scales) accounting for ≥0.4% of the phenotypic variance in temperament scales. Using meta-analysis techniques, gene-based tests and pathway analysis we have tested over 1.2 million single-nucleotide polymorphisms (SNPs) for association to each of the four temperament dimensions. We did not discover any SNPs, genes, or pathways to be significantly related to the four temperament dimensions, after correcting for multiple testing. Less than 1% of the variability in any temperament dimension appears to be accounted for by a risk score derived from the SNPs showing strongest association to the temperament dimensions. Elucidation of genetic loci significantly influencing temperament and personality will require potentially very large samples, and/or a more refined phenotype. Item response theory methodology may be a way to incorporate data from cohorts assessed with multiple personality instruments, and might be a method by which a large sample of a more refined phenotype could be acquired.

Farming environment and prevalence of atopy at age 31: prospective birth cohort study in Finland

BACKGROUND

Cross-sectional studies have shown an association between the farming environment and a decreased risk of atopic sensitization, mainly related to contact with farm animals in the childhood.

OBJECTIVE

Investigate the association of a farming environment, especially farm animal contact, during infancy, with atopic sensitization and allergic diseases at the age of 31.

METHODS

In a prospective birth cohort study, 5509 subjects born in northern Finland in 1966 were followed up at the age of 31. Prenatal exposure to the farming environment was documented before or at birth. At age 31, information on health status and childhood exposure to pets was collected by a questionnaire and skin prick tests were performed.

RESULTS

Being born to a family having farm animals decreased the risk of atopic sensitization [odds ratio (OR) 0.67; 95% confidence interval (CI) 0.56-0.80], atopic eczema ever (OR 0.77; 95% CI 0.66-0.91), doctor-diagnosed asthma ever (OR 0.74; 95% CI 0.55-1.00), allergic rhinitis at age 31 (OR 0.87; 95% CI 0.73-1.03) and allergic conjunctivitis (OR 0.86; 95% CI 0.72-1.02) at age 31. There was a suggestion that the reduced risk of allergic sensitization was particularly evident among the subjects whose mothers worked with farm animals during pregnancy, and that the reduced risk of the above diseases by farm animal exposure was largely explained by the reduced risk of atopy. Having cats and dogs in childhood revealed similar associations as farm animals with atopic sensitization.

CONCLUSION AND CLINICAL RELEVANCE

Contact with farm animals in early childhood reduces the risk of atopic sensitization, doctor-diagnosed asthma and allergic diseases at age 31.

Is prenatal alcohol exposure related to inattention and hyperactivity symptoms in children? Disentangling the effects of social adversity

BACKGROUND

Studies concerning whether exposure to low levels of maternal alcohol consumption during fetal development is related to child inattention and hyperactivity symptoms have shown conflicting results. We examine the contribution of covariates related to social adversity to resolve some inconsistencies in the extant research by conducting parallel analyses of three cohorts with varying alcohol consumption and attitudes towards alcohol use.

METHODS

We compare three population-based pregnancy-offspring cohorts within the Nordic Network on ADHD from Denmark and Finland. Prenatal data were gathered via self-report during pregnancy and birth outcomes were abstracted from medical charts. A total of 21,678 reports concerning inattention and hyperactivity symptoms in children were available from the Strengths and Difficulties Questionnaire or the Rutter Scale completed by parents and/or teachers.

RESULTS

Drinking patterns differed cross-nationally. Women who had at least some social adversity (young, low education, or being single) were more likely to drink than those better off in the Finnish cohort, but the opposite was true for the Danish cohorts. Prenatal alcohol exposure was not related to risk for a high inattention-hyperactivity symptom score in children across cohorts after adjustment for covariates. In contrast, maternal smoking and social adversity during pregnancy were independently and consistently associated with an increase in risk of child symptoms.

CONCLUSIONS

Low doses of alcohol consumption during pregnancy were not related to child inattention/hyperactivity symptoms once social adversity and smoking were taken into account.

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 and five other previously published definitions.

DESIGN

Cross-sectional survey in the prospective general population-based Northern Finland Birth Cohort 1986 (NFBC 1986) at age 16 years.

SETTING

Birth cohort in Finland.

PARTICIPANTS

5665 adolescents (2862 males and 2803 females) clinically examined in 2001-2002.

MAIN OUTCOME MEASURES

The prevalence of MS using different definitions.

RESULTS

The overall prevalence of MS using the IDF paediatric definition was 2.4% (95% CI 2.0 to 2.8%) at the age of 16 years. Using the IDF adult definition the overall prevalence was lower, 1.7% (CI 1.3 to 2.0%, European cut-offs for waist circumference) and 1.0% (CI 0.7 to 1.3%, North American cut-offs).

CONCLUSION

In 16-year-old adolescents, the paediatric IDF definition rendered a higher prevalence estimate than the adult definition.

Association of variants in the fat mass and obesity associated (FTO) gene with polycystic ovary syndrome

AIMS/HYPOTHESIS

Variants in the fat-mass and obesity-associated gene (FTO) influence susceptibility to type 2 diabetes via an effect on adiposity/obesity. Given the important role of obesity in the aetiology of both polycystic ovary syndrome (PCOS) and type 2 diabetes mellitus, our aim was to establish whether FTO variants are also implicated in PCOS susceptibility.

METHODS

We performed a genetic association study of FTO variant rs9939609 using case-control analyses, conducted in 463 PCOS patients (geometric mean BMI 27.5 kg/m(2)) and 1,336 female controls (geometric mean BMI 25.3 kg/m(2)) of UK British/Irish origin. We also sought evidence for associations between FTO variation and circulating testosterone levels in 324 UK PCOS patients and 1,000 women from the Northern Finland Birth Cohort of 1966. Outcome measures included FTO rs9939609 genotype frequencies by participant group and androgen measures (testosterone, free androgen index) by genotype.

RESULTS

There was a significant association between FTO genotype and PCOS status in the UK case-control analysis, which was attenuated by adjustment for BMI (Cochran-Armitage test, odds ratio [per minor allele copy] 1.30 [95% CI 1.12, 1.51], p = 7.2 x 10(-4) [unadjusted], p = 2.9 x 10(-3) [adjusted]). This association was most evident in obese PCOS patients (PCOS patients below median BMI vs UK controls, p = 0.11; above median BMI vs controls, p = 2.9 x 10(-4)). No relationship between FTO genotype and androgen levels was seen.

CONCLUSIONS/INTERPRETATION

We provide the first evidence that variants that predispose to common obesity also result in altered susceptibility to PCOS, confirming the mechanistic link between these conditions. The predominant effect of FTO variants on PCOS susceptibility is probably mediated through adiposity.

No evidence that established type 2 diabetes susceptibility variants in the PPARG and KCNJ11 genes have pleiotropic effects on early growth

AIMS/HYPOTHESIS

The P12A variant in the PPARG gene and the E23K polymorphism in KCNJ11 are both known to influence individual predisposition to type 2 diabetes. If the effect of these variants on insulin secretion and action were to extend to an influence on early growth (which is largely mediated by insulin), it would offer an explanation for observed associations between low birthweight and subsequent diabetes. Since previous studies of the effects of these variants on early growth have been limited and conflicting, we examined these associations in a large, well-characterised birth cohort.

METHODS

The P12A and E23K variants were genotyped in (respectively) 5,652 and 5,632 individuals from the Northern Finland Birth Cohort of 1966 and we sought associations with early growth phenotypes.

RESULTS

Neither variant was associated with birthweight (P12A, p = 0.42; E23K, p = 0.44, additive models) or other measures of early growth. Although a previous report had suggested that the P12A effect on adult insulin sensitivity was restricted to small babies, we were unable to reproduce this finding (p = 0.40), nor did we confirm a previous report of an association with gestational age (p = 0.23).

CONCLUSIONS/INTERPRETATION

Despite a larger sample size than previous studies, we were unable to detect any effect of these variants on early growth. These findings do not support the notion that there are shared genetic determinants of low birthweight and adult diabetes.

Disparate genetic influences on polycystic ovary syndrome (PCOS) and type 2 diabetes revealed by a lack of association between common variants within the TCF7L2 gene and PCOS

AIMS/HYPOTHESIS

Common variants of the gene encoding transcription factor 7-like 2 (TCF7L2) have a powerful effect on individual risk of type 2 diabetes (per allele odds ratio approximately 1.35). Polycystic ovary syndrome (PCOS) and type 2 diabetes are familial conditions sharing common features. Based on this, the aim of the present study was to establish whether variation in TCF7L2 also influences the development of PCOS.

METHODS

We conducted a genetic association study of variants of TCF7L2 (rs7903146 and rs12255372) using both case-control and quantitative trait approaches. Case-control analyses were conducted in (1) 369 PCOS cases and 2574 controls of UK British/Irish origin, and (2) 540 women with PCOS symptoms and 1083 controls from the Northern Finland Birth Cohort of 1966. Quantitative trait analyses (androgen levels) were also performed (1249 individuals).

RESULTS

There was no association between rs7903146 and PCOS in the UK case-control study (Cochran-Armitage test, p = 0.51); nor with symptomatic status in the Finnish cohort (p = 0.36). In addition, there were no relationships between the TCF7L2 single nucleotide polymorphism rs7903146 and androgen levels (UK cases, p = 0.99; Finnish controls, p = 0.57; Finnish symptomatic cases, p = 0.80). Results at rs12255372 were similar, reflecting strong linkage disequilibrium with rs7903146.

CONCLUSIONS/INTERPRETATION

Our study was powered to detect an effect on PCOS susceptibility similar to that previously reported for these variants on type 2 diabetes. Failure to detect any evident association with PCOS provides the strongest evidence yet that the genetic architecture of these related conditions is qualitatively distinct.

Cardiorespiratory Fitness of Finnish Adolescents

We evaluated the accuracy of a submaximal cycle ergometer test to assess cardiorespiratory fitness in adolescents and provided population-based reference values. In a health study of the Northern Finland birth cohort born in 1985 - 1986 (NFBC 1986), cardiorespiratory fitness of 5375 males and females aged 15 to 16 years was measured by a submaximal cycle ergometer test by using a two-stage exercise protocol designed for this survey. A total of 4903 subjects performed two work stages. Maximal workload and peak oxygen consumption were calculated on the basis of heart rate responses by the WHO extrapolation method. An additional 472 subjects were able to finish only one work stage. For them, peak oxygen uptake was calculated by the Astrand nomogram. To evaluate the accuracy of submaximal testing, a validation sample of 90 subjects carried out both a submaximal test and a maximal cycle ergometer test with direct measurement of peak oxygen uptake. The WHO method proved to estimate peak oxygen uptake with reasonable accuracy. The Astrand nomogram method overestimated peak oxygen uptake considerably, and therefore a new single-stage regression method was applied to calculate maximal workload and peak oxygen consumption. Reference values of cardiorespiratory fitness were provided for 2690 males and 2685 females aged 15 to 16 years.

Factors associated with fall in neonatal intubation rates in the United Kingdom - prospective study

OBJECTIVE

To investigate the trend of neonatal resuscitation by intubation or mask ventilation over time and to assess its association with changes in prevalence of caesarean section and use of general anaesthesia in labour.

METHODS

All women booking pregnancy at any of 15 maternity units, analysed using logistic regression.

DESIGN

Prospective study.

SETTING

UK hospital-based maternity units (15 centres).

POPULATION

A total of 221,322 first singleton births of babies weighing 200 g or more in the St Mary's Maternity Information System cohort, 1988-2000, covering the North West Thames area of London.

MAIN OUTCOME MEASURES

Prevalence of intermittent positive-pressure ventilation (IPPV) (by intubation or mask) by calendar year.

RESULTS

Overall use of IPPV decreased markedly (two-sided P<0.01) over the course of the study, and this decrease was evident by all modes of delivery. Adjusted mean prevalence of intubated IPPV decreased from 0.51% (95% CI 0.44-0.58) in 1988 to 0.07% (95% CI 0.06-0.09) in 2000. There was a similar decrease in the prevalence of IPPV by mask. However, despite substantial increases in prevalence of caesarean sections and reductions in the use of general anaesthesia over the course of the study, adjusting for these variables made little difference to the temporal trends in intubation or use of mask ventilation.

CONCLUSIONS

There has been a marked reduction in the prevalence of infants given resuscitation by positive-pressure ventilation that cannot be explained by changes in the prevalence of caesarean section or use of general anaesthesia in labour.

Does vitamin D supplementation in infancy reduce the risk of pre-eclampsia?

Vitamin D has been suggested to affect the balance between T helper (Th1) and (Th2) type cytokines by favouring Th2 domination. We investigated the association between infant vitamin D supplementation and later pre-eclampsia, a disorder suggested to be dominated by Th1 response. We used data on 2969 women born in the Northern Finland Birth Cohort 1966 of whom 68 (2.3%) had pre-eclampsia in their first pregnancy. Risk of pre-eclampsia was halved (OR 0.49, 95% confidence interval (CI) 0.26-0.92) in participants who had received vitamin D supplementation regularly during the first year of life and this association was not affected by adjustment for own birth order, birth weight, gestational age, social class in 1966 and hospitalizations or pregnancy-induced hypertension of their mothers. Together with earlier observations on a reduced risk of type 1 diabetes after vitamin D supplementation, these data suggest that vitamin D intake in infancy may affect long-term programming of the immune response pattern.

Gingivitis, dental caries and tooth loss: risk factors for cardiovascular diseases or indicators of elevated health risks

OBJECTIVES

The results of earlier studies connecting dental diseases to cardiovascular diseases are inconsistent. Our aim in this cross-sectional study was to investigate whether there are associations of dental diseases and diagnosed angina pectoris among the 1966 Northern Finland Birth Cohort.

MATERIALS AND METHODS

A postal questionnaire was sent to all cohort members in 1997-1998. The number of replies totalled 8690. Angina pectoris was determined by asking whether the respondent had been diagnosed with angina pectoris. Gingivitis, dental caries and tooth loss were determined on the basis of self-reported gingival bleeding, presence of dental caries and six or more missing teeth.

RESULTS

We found overall associations of gingivitis (odds ratio (OR) 1.52, confidence interval (CI) 1.04-2.22), dental caries (OR 1.50, CI 1.04-2.18) and tooth loss (OR 1.53, CI 0.69-3.42) with the presence of angina pectoris. The associations were modified by gender and socioeconomic status. In addition, gingivitis, dental caries and tooth loss were also associated with several cardiovascular risk factors.

CONCLUSION

There were associations of self-reported gingivitis, dental caries and tooth loss with angina pectoris. However, the associations between dental diseases and cardiovascular risk factors suggest that the associations may be because of confounding.

Body size from birth to adulthood and bone mineral content and density at 31 years of age: results from the northern Finland 1966 birth cohort study

The purpose of this study was to evaluate the association between body size from birth to adulthood and bone mineral content (BMC) and bone mineral density (BMD) at the age of 31 years in a longitudinal study of the Northern Finland birth cohort for 1966. Data were collected at birth, 1, 14, and 31 years. This analysis was restricted to a subsample of individuals (n =1,099) for whom the BMC (g) and BMD measurements (g/cm(2)) were performed on the distal and ultradistal radius by dual-energy X-ray absorptiometry (DXA) at the age of 31 years. Determinants of low BMC and BMD were analyzed using multivariate logistic regression. Growth retardation at birth, being underweight (BMI < or =20.0 kg/m(2)) at 31 years, and having a low calcium intake at 31 years were associated independently with low BMD at 31 years. Additionally, the proportion of subjects with low BMD was higher among those who had low standardized body weight (< or =1 SD) both at birth and at 14 years, and both at 14 and 31 years. Body weight at 31 years was the strongest associating factor of BCM at 31 years. Growth retardation at birth has long-lasting effects on adult bone mineral content and density of the distal and ultradistal radius independently of later body size, although adult body weight seems to be a most important determinant of BMC at the age of 31 years. Thinness and a low calcium intake are associated with low bone mineral content and density at 31 years of age. Further studies are needed to evaluate if these groups are at increased risk of osteoporosis in old age.

No association between insulin gene variation and adult metabolic phenotypes in a large Finnish birth cohort

AIMS/HYPOTHESIS

Although the variable number tandem repeat (VNTR) minisatellite 5' to the insulin gene is among the most studied polymorphisms in diabetes, the relationships between VNTR variation, diabetes-related traits and predisposition to type 2 diabetes remain unclear. Since inadequate sample size is likely to have been an obstacle to reliable inference, we examined the relationship between VNTR variation and a range of diabetes-related traits in a cohort of 5,753 Finnish adults.

MATERIALS AND METHODS

VNTR genotypes were derived, by typing at the -23HphI variant site, for 5,646 individuals from the Northern Finland Birth Cohort 1966. Associations were sought between these genotypes and a range of anthropometric (BMI, WHR), physiological (blood pressure) and biochemical (fasting glucose, insulin, lipids, indices of insulin sensitivity and beta cell function) measures obtained at clinical examination at 31 years.

RESULTS

We found no evidence that VNTR genotype was significantly associated with measures of insulin secretion, insulin sensitivity, glycaemia, adiposity or blood pressure.

CONCLUSIONS/INTERPRETATION

Despite evidence from several relatively small studies suggesting that INS-VNTR genotypes are associated with predisposition to type 2 diabetes, reduced beta cell function and measures of adiposity, the present study failed to detect any association with a range of diabetes-related traits. Taken with other recent studies in large population-based cohorts, these data suggest that previous studies have, at the very least, overestimated the influence of the INS-VNTR on type 2 diabetes-related traits. The effects of INS-VNTR variation on insulin transcription observed in vitro appear not to translate into detectable differences in basal insulin secretion in humans.

How do persons with intellectual disability manage in the open labour markets? A follow-up of the Northern Finland 1966 Birth Cohort

BACKGROUND

The aim was to study how many of the individuals with intellectual disability (ID; IQ < or = 70) in an age cohort were not receiving a disability pension by the age of 34 years and what their life situation was like in terms of employment, education and morbidity. In 2000, the Northern Finland 1966 Birth Cohort (n=12,058 live-born) included 129 individuals with ID.

METHOD

The outcome data on employment, education, pensions and morbidity were obtained from national registers.

RESULTS

A total of 85.3% (n=110) of all the individuals with ID were on pension, and 66 of them had severe ID (IQ <50) and 44 had mild ID (IQ 50-70). Altogether 99 were drawing a pension because of ID, and 11 had a main diagnosis other than ID in the register of Social Insurance Institution. Nineteen individuals with mild ID were not on disability pension. The educational level of those without pension was low, and all whose occupation was known worked in low-level manual trades in the open labour market. During the past 8 years (1993-2000), their employment rate had been lower and unemployment rate correspondingly higher and unemployment periods longer than those of the reference group (IQ >85 or not measured). As to the morbidity, they had been hospitalized twice more often than those in the reference group and the mean of their hospitalization days was over fourfold.

CONCLUSION

More attention should be paid to the vocational education and supported employment services of individuals with ID to help them to manage as independently as possible.

Antibodies to Chlamydia trachomatis heat shock proteins Hsp60 and Hsp10 and subfertility in general population at age 31

PROBLEM

To assess the association between antibodies to Chlamydia trachomatis heat shock proteins 60 and 10 (Hsp60 and Hsp10) and subfertility in a general population sample.

METHOD OF STUDY

A nested case (n = 146)-control (n = 278) study in a population-based birth cohort. Serum immunoglobulin (Ig)G and IgA antibodies against C. trachomatis Hsp60 and Hsp10, explanatory factors, were measured by enzyme immunoassay, using recombinant proteins as antigens. The main outcome variable was subfertility (time to pregnancy > or =12 months).

RESULTS

The prevalence and medians of serum IgA antibodies to Hsp60 and Hsp10 were significantly higher in the female partners of subfertile couple than in their fertile controls. On the contrary, among male partners of subfertile couple, especially among smokers serum antibody levels to Hsp antigens were lower than in the controls.

CONCLUSION

The results indicate a serological association of antibodies to chlamydial Hsp antigens with female subfertility in a population-based sample.

Association between Chlamydia trachomatis antibodies and subfertility in the Northern Finland Birth Cohort 1966 (NFBC 1966), at the age of 31 years

The objective of this study was to assess the serological association between previous Chlamydia trachomatis infection and subfertility in a general population sample. A nested case (n = 493)-control (n = 986) study in a population-based birth cohort consisting of 12,058 live births from the year 1966 was conducted. The analysis was restricted to those 6007 cohort members who replied to a postal inquiry and participated in a health examination including blood samples at the age of 31 years. The presence of C. trachomatis-specific serum IgG antibodies was screened by a synthetic peptide-based enzyme-linked immunosorbent assay. All the positive sera were further tested by the microimmunofluorescence method using immunotype pools and individual immunotypes of C. trachomatis as antigens. An association was found between the detection of immunotype-specific C. trachomatis antibodies and subfertility both in men and women. The results of the present study confirm the serological association between past C. trachomatis infections and subfertility in male or female partners of the couple in the population-based sample.

Serum lipids in schizophrenia and other functional psychoses: a general population northern Finland 1966 birth cohort survey

OBJECTIVE

To compare fasting serum lipid concentrations of subjects with schizophrenia with a comparison group.

METHOD

The study sample consists of 5654 members of the northern Finland 1966 birth cohort who participated in the field study with blood samples after overnight fasting and clinical examination in 1997-98. Total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides (TG) and glucose were analyzed. Analysis of variance were used for comparing differences in lipids means between diagnostic categories.

RESULTS

Mean fasting TC in subjects with schizophrenia was 20 mg/dl higher than in the comparison group. TC and TG levels in the group of other psychoses resembled the schizophrenia group.

CONCLUSION

Blood lipid levels in subjects with schizophrenia and other functional psychoses were high. As these persons are at special risk for hyperlipidemia their lipid levels should be regularly monitored, and cholesterol lowering diet, as well as medication, should be considered.

Health care costs resulting from IVF: prenatal and neonatal periods

BACKGROUND

The use of expensive infertility treatments is increasing rapidly. To compare the prenatal and neonatal health care costs after IVF and spontaneous conception, we conducted a study based on a cohort of IVF and control pregnancies and neonates.

METHODS

A cohort of 215 IVF mothers and 255 IVF neonates were compared with a cohort of 662 control mothers and 388 control children, randomly chosen from the Finnish Medical Birth Register and matched for sex, year of birth, area of residence, parity, maternal age, socioeconomic status and plurality. The analyses on prenatal and neonatal costs were performed by plurality. Singletons were also compared with twins. The cost calculations were based on the known level of utilization of maternal and neonatal health care services.

RESULTS

The total health care costs for an IVF singleton until the end of the neonatal period were 5780 and 15 580 for an IVF twin. The health care costs were 1.3-fold for IVF singletons and 1.1-fold for IVF twins compared to control singletons and twins. The costs for twins were approximately 3-fold compared to singletons.

CONCLUSIONS

The health care costs of an IVF singleton neonate were higher than those of a spontaneously conceived control neonate with similar backgrounds. For twins the health care costs were equal. Multiple births increase the health care costs and therefore the reduction of multiple pregnancies is the most effective way to reduce the health care costs resulting from IVF.

A large population cohort provides normative data for investigation of temperament

OBJECTIVE

We evaluated the psychometric properties of widely used scales for assessing temperament in a large birth cohort. We simultaneously compared the properties of the temperament dimensions of the Tridimensional Personality Questionnaire (TPQ) and of the Temperament and Character Inventory (TCI).

METHOD

As part of the 31-year follow-up survey of the prospective Northern Finland 1966 Birth Cohort, the TPQ and TCI temperament questions were filled in by 4349 subjects (1974 males, 2375 males). Factor analysis and Cronbach's alpha were used to explore the psychometric properties of the scales.

RESULTS

Of the three higher-order dimensions the reward dependence (RD) was the only one performing poorly in our study sample. Cronbach's alpha was higher in the TCI than in the TPQ.

CONCLUSION

The results indicate good performance of the TCI and TPQ. Factor analysis support adoption of four temperament dimensions and suggest that developmental work is still needed in the RD dimension.

Growth, psychomotor development and morbidity up to 3 years of age in children born after IVF

BACKGROUND

To examine the long-term child outcome after IVF until the age of 3 years in Northern Finland, we conducted a population-based cohort study.

METHODS

First, a cohort of 299 IVF children born in 1990-1995 was compared with a cohort of 558 controls representing the general population in terms of a multiple birth rate of 1.2%, randomly chosen from the Finnish Medical Birth Register (FMBR) and matched for sex, year of birth, area of residence, parity, maternal age and social class (full sample analyses). Second, IVF singletons (n = 150) were compared with singleton controls (n = 280). Third, a plurality matched control cohort (n = 100) for IVF twins (n = 100) was randomly chosen, matched as above, from the FMBR and analysed separately. Infant mortality rate was compared with the national rate from the FMBR.

RESULTS

Infant mortality in the IVF group was >2-fold higher compared to the national rate in the general population. The risk (OR, 95% CI) of low weight and height, below the lowest quartile, at 1 year of age (1.6, 1.1-2.2; 1.6, 1.1-2.4) and 2 years of age (1.5, 1.1-2.4; 1.7, 1.2-2.5) was significantly higher in the IVF group when compared with the general population control group. No statistically significant differences were found in the psychomotor development between the cohorts. Cumulative incidence of different diseases up to 3 years of age was significantly higher among IVF children in the full sample and singleton analyses (OR, 95% CI: 2.3, 1.7-3.2; 2.1, 1.3-3.3 respectively) especially regarding respiratory diseases (3.5, 1.9-6.5; 3.1, 1.0-9.4) and diarrhoea (3.7, 2.2-6.2; 5.7, 2.6-12.7), but not in twin comparisons.

CONCLUSIONS

The growth of IVF children was behind that of control children during the first 3 years of life, but their psychomotor development was similar. Their postnatal health was worse, probably reflecting the problems in the neonatal period.

Is a large family a protective factor against behavioural and emotional problems at the age of 8 years?

AIM

To study the prevalence of behavioural and emotional problems among children from different family types, sibship size and birth order.

METHODS

A prospective birth cohort (n = 9357) study where parents filled in two questionnaires and teachers assessed children's behaviour using the Rutter scale (RB2).

RESULTS

14.3% scored above the cut-off point (RB2 > or = 9) indicating probable psychiatric disturbance, boys more often than girls (OR 2.6, 95% CI 2.3-3.0). Behavioural problems (9.2%) were more common than emotional ones (4.1%). Boys living in families other than two-parent families were at risk for probable psychiatric disturbance, and a corresponding risk was observed for girls living in single-parent or always one-parent families. Other than two-parent family was also a risk for behavioural problems; for boys adjusted odds ratios ranged significantly from 1.8 to 2.4 and for girls from 2.0 to 3.7. "Only children" had the highest prevalence of behavioural problems, while children in very large families had the lowest. Living in a very large family was a protective factor against behavioural problems among boys but not among girls. Eldest children were at lower risk of behavioural problems than the other children. The single-parent and always one-parent family was associated with higher risk of emotional problems among girls.

CONCLUSION

Children's psychiatric problems are manifested at school mostly as behavioural problems. A two-parent family and being the oldest in the sibling series seem to be protective factors. Very large family size, if not connected to social disadvantages, does not seem to be a risk factor for children's behaviour.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Predictors of abdominal obesity among 31-y-old men and women born in Northern Finland in 1966

OBJECTIVE

To find predictors of abdominal obesity (defined by >90th percentile of waist/hip ratio (WHR)) and related factors among 31-y-old men and women.

DESIGN

Longitudinal study of the northern Finland birth cohort of 1966 with measurements obtained at birth, 14 and 31 y.

SUBJECTS

A total of 2841 men and 2930 women with data on WHR at 31 y.

RESULTS

The most important predictor of abdominal obesity among the 31-y-old men was a high body mass index (BMI), those with normal weight at 14 y who were obese at 31 y having an especially high risk of abdominal obesity at 31 y. Abdominal obesity was independently associated with current weight status, small size for gestational age, a high intake of alcohol at 31 y, physical inactivity at 31 y, unhealthy diet in the sense of infrequent consumption of fiber-rich foods and frequent consumption of sausages, and a low level of occupational training. Physical inactivity and minimal vocational training also tended to be associated with abdominal obesity among women. The analyses were controlled for maternal age and BMI, and also for hormonal contraception and parity among women.

CONCLUSIONS

Some aspects of risk of adult abdominal obesity were evident during adolescence, and good advice is needed then, and in early adulthood, in order to reduce the risk of abdominal obesity in their thirties. Those who are small for gestational age are vulnerable to the development of abdominal obesity. Successful weight control from adolescence to adulthood, and healthy eating, alcohol drinking and exercise habits are important for avoiding abdominal accumulation of body fat.

The Finnish version of The National Institutes Of Health Chronic Prostatitis Symptom Index correlates well with the visual pain scale: translation and results of a modified linguistic validation study

Authors from Finland have assessed a version in their language of the National Institutes of Health-Chronic Prostatitis Symptom Index; they found that their translated version was valid and easily understandable in the management of the symptoms of chronic pelvic pain syndrome. They felt it should be used as a primary outcome measure in studies with these patients. There are three papers in this issue relating to the effect of drugs on LUTS; the first of these is a pooled analysis of three double-blind placebo-controlled studies into the safety and efficacy of the 10 mg dose of alfuzosin. The second evaluates the effect on quality-of-life issues of treatment with dutasteride. Finally, authors from Australia compare the effect of a Serenoa repens extract with placebo for LUTS.

OBJECTIVES

To provide a fluent and easily comprehensible Finnish version of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) and to study its linguistic validity and correlation with a visual pain scale (VAS).

PATIENTS AND METHODS

The double-back translation method with two interim modifications was used to produce the Finnish version of the NIH-CPSI. The validity was tested by presenting the questionnaire to 155 men with clinically confirmed chronic pelvic pain syndrome (CPPS) and 12 controls with no previous urological symptoms. Convergent validity of the NIH-CPSI was tested by determining the correlation between the Finnish NIH-CPSI and VAS. Patients' and urologists' opinions about the utility of the Finnish NIH-CPSI were also reviewed.

RESULTS

The total Finnish NIH-CPSI scores and the pain domain and voiding symptom domain scores differed significantly (P < 0.001) between the groups, suggesting good discriminant validity of the symptom index. The NIH-CPSI scores correlated well with the VAS (Pearson's correlation 0.76). The preciseness and comprehensibility of the questionnaire were consistently evaluated to be 'good' or 'excellent' both by patients and urologists.

CONCLUSIONS

The Finnish version of the NIH-CPSI is valid and easily comprehensible for measuring CPPS symptoms. In addition, it provides good discriminant and convergent validity in distinguishing CPPS symptoms and should be used as primary outcome measure in CPPS studies.

Body size from birth to adulthood as a predictor of self-reported polycystic ovary syndrome symptoms

OBJECTIVE

To study the association between body size from birth to adulthood and self-reported symptoms of polycystic ovary syndrome (PCOS), particularly hirsutism and menstrual disturbances.

DESIGN

Longitudinal, population-based study of a cohort of women born in 1966 in northern Finland. The study population included 2007 women who were not pregnant and did not use hormonal contraception. Of these 528 (26%) had self-reported symptoms of PCOS.

RESULTS

Weight at birth, gestational age, being small for gestational age or growth retardation at birth were not associated with PCOS symptoms at 31 y. An increased risk of PCOS symptoms was observed among women with abdominal obesity (waist/hip ratio >85th percentile) at 31 y who had normal weight in adolescence and were overweight (body mass index (BMI) 25.0-29.9 kg/m(2)) or obese (BMI>30.0 kg/m(2)) at 31 y (relative risk (RR) (95% CI) 1.44(1.10-1.89)), and among women with abdominal obesity who were overweight or obese at both 14 and 31 y (1.71 (1.30-2.24)). A total of 30% and 41% of the women with PCOS symptoms in these groups could be attributed, respectively, to overweight, obesity and abdominal obesity at 31 y.

CONCLUSIONS

These results suggest that obesity in adolescence and in adulthood, and also weight gain after adolescence, particularly in the presence of abdominal obesity, are associated with self-reported PCOS symptoms in adulthood. Thus, based on the results from intervention studies treating PCOS and the results of this study, the prevention of obesity and abdominal obesity is important among young women.

Unemployment and obesity among young adults in a northern Finland 1966 birth cohort

OBJECTIVE

To establish (1) if obesity in adolescence predicts a long history of unemployment and other adverse social outcomes at age 31 y and, conversely, (2) the effect of a long history of unemployment on the risk of obesity at 31 y.

DESIGN AND SUBJECTS

A longitudinal, population-based study of 9,754 subjects born in 1966 in Northern Finland was conducted. The cohort members were studied at birth, 1, 14 and 31 y.

MEASUREMENTS

Body mass index (BMI) at 14 and 31 y; work history, as self-reported at 31 y and as recorded in national registers of the total number of days each subject had received unemployment allowance between 1985 and 1997; place of residence at 14 and 31 y; family social class at 14 y; subject's school performance at 16 y; marital status and number of children at 31 y.

RESULTS

Overweight and obesity at 14 y did not predict a long history of unemployment at 31 y, but were associated with a low level of education, and being single or divorced at 31 y among females. A long history of unemployment (register data) was associated with an increased risk of obesity among women, but not men, after controlling for potential confounding factors (social class at 14 y, BMI at 14 y, school performance at 16 y, place of residence, and number of children). The adjusted OR (95% CI) was 1.09 (0.72-1.63) for men, and 1.64 (1.07-2.50) for women.

CONCLUSION

Adverse social outcomes of adolescent obesity seemed to emerge more for women. Subjects with low school performance and women with a long unemployment history are at increased risk of obesity.

Linguistic skills in relation to neurological findings at 8 years of age in children born preterm

The linguistic skills of 8-year-old children born preterm (n = 42) with birthweight < 1750 grams from a 1-year birth cohort for 1985-86 in northern Finland were studied with three different language tests, namely the Illinois Test of Psycholinguistic Abilities (ITPA), the Token Test for Children (TTC) and the Morphological Test (MT) for Finnish children. Full-term control children (n = 42) with birthweight > or = 2500 grams from the same birth cohort were matched individually with their preterm pairs for age, sex, twinship, mother's education, place of residence, birth order and family type. The preterm children's language abilities were studied in relation to their neurological status and to the periventricular leukomalacia (PVL) findings of magnetic resonance imaging (MRI). The preterm children with minor neurodevelopmental dysfunctions (MND) scored worst and differed significantly from their matched controls in TTC. They also differed significantly from other preterm subgroups, namely healthy preterm and preterm children with cerebral palsy (CP), in verbal comprehension measured by TTC. PVL findings were not associated with performance in the language ability tests. A closer and regular follow-up of language development in the MND-disabled group among the low-birthweight preterm children is recommended.

Coping of parents with physically and/or intellectually disabled children

OBJECTIVE

The aim was to clarify how families with physically and/or intellectually disabled children cope, what kind of coping strategies they use and how the families with good and poor coping capacities differ.

METHODS

The parents of eight children (aged 8-10 years) with physical and/or intellectual disability were interviewed twice, and the data elicited in these interviews were analysed qualitatively using the grounded theory method.

RESULTS

Information and acceptance, good family co-operation and social support were related to the coping strategies most frequently used. Half of the families seemed to have found successful ways of coping, whereas another half had major problems. There were five main domains in which the high- and low-coping families differed most from each other: (1) parents' initial experiences; (2) personal characteristics; (3) effects of the child's disability on family life; (4) acting in everyday life; and (5) social support.

CONCLUSION

The findings can be utilized in developing supportive activities for families with disabled children. By recognizing the coping strategies used by the family, professionals and service providers can find the right ways to support their adaptation. As the role of physicians, nursing staff and other professionals in this process is very important, more attention should be attached to the collaboration between these groups, to enable them to view the situation from the perspective of the whole family.

Linguistic and motor abilities of low-birthweight children as assessed by parents and teachers at 8 years of age

Linguistic and motor abilities among low-birthweight 8-y-old children in the northern Finland Birth Cohort for 1985-1986 (n = 9322) were studied using parental and teacher evaluations. The parents of 8370 (90%) and teachers of 8525 (92%) children returned a mailed questionnaire concerning the children's speech, language, learning and motor abilities. Low-birthweight (LBW, < 2500 g) children (n = 279) appeared to have experienced more difficulties than normal-birthweight (NBW, > or = 2500 g) children (n = 8091). The parents evaluated the LBW boys to be the poorest in linguistic and motor skills compared with the other boys or any of the groups of girls. They are therefore presumably at risk of having problems at school, which was confirmed by the teachers' reports. There was also a clear relationship between speech/linguistic and motor disabilities.

CONCLUSION

Multivariate logistic regression analyses showed that the lower birthweight and some sociodemographic factors, for example the mother's age being between 20 and 24 y, having more than four children in the family, a reconstructed family, as well as hearing impairment and male gender were the most important determinants of poor speech and language abilities at 8 y of age, with and without adjustment for neonatal risk factors (asphyxia, convulsions, respiratory distress syndrome, bronchopulmonary dysplasia, patent ductus arteriosus). Smallness for gestational age was also a risk factor for poor speech and language skills. Preterm birth was associated with poor skills only after adjustment for the neonatal risk factor. The parental and teacher evaluations were concordant concerning the LBW children's outcome.

Intake of vitamin D and risk of type 1 diabetes: a birth-cohort study

BACKGROUND

Dietary vitamin D supplementation is associated with reduced risk of type 1 diabetes in animals. Our aim was to ascertain whether or not vitamin D supplementation or deficiency in infancy could affect development of type 1 diabetes.

METHODS

A birth-cohort study was done, in which all pregnant women (n=12055) in Oulu and Lapland, northern Finland, who were due to give birth in 1966 were enrolled. Data was collected in the first year of life about frequency and dose of vitamin D supplementation and presence of suspected rickets. Our primary outcome measure was diagnosis of type 1 diabetes by end of December, 1997.

FINDINGS

12058 of 12231 represented live births, and 10821 (91% of those alive) children were followed-up at age 1 year. Of the 10366 children included in analyses, 81 were diagnosed with diabetes during the study. Vitamin D supplementation was associated with a decreased frequency of type 1 diabetes when adjusted for neonatal, anthropometric, and social characteristics (rate ratio [RR] for regular vs no supplementation 0.12, 95% CI 0.03-0.51, and irregular vs no supplementation 0.16, 0.04-0.74. Children who regularly took the recommended dose of vitamin D (2000 IU daily) had a RR of 0.22 (0.05-0.89) compared with those who regularly received less than the recommended amount. Children suspected of having rickets during the first year of life had a RR of 3.0 (1.0-9.0) compared with those without such a suspicion.

INTERPRETATION

Dietary vitamin D supplementation is associated with reduced risk of type 1 diabetes. Ensuring adequate vitamin D supplementation for infants could help to reverse the increasing trend in the incidence of type 1 diabetes.