Age-dependency in mortality of Finnish family caregivers: a nationwide register-based study

Purpose

Mortality appears to be lower in family caregivers than in the general population. However, there is lack of knowledge whether the difference in mortality between family caregivers and the general population is dependent on age. The purpose of this study was to analyze all-cause mortality in relation to age in family caregivers and to study their cause-specific mortality using data from multiple Finnish national registers.

Methods

The data included all individuals, who received family caregiver's allowance in Finland in 2012 (n = 42 256, mean age 67 years, 71% women) and a control population matched for age, sex, and municipality of residence (n = 83 618). Information on dates and causes of death between 2012 and 2017 were obtained from the Finnish Causes of Death Register. Flexible parametric survival modeling and competing risk regression adjusted for socioeconomic status were used.

Results

The total follow-up time was 717 877 person-years. Family caregivers had lower all-cause mortality than the controls over the follow-up (8.1% vs. 11.6%) both among women (hazard ratio [HR]: 0.64, 95% CI: 0.61-0.68) and men (HR: 0.73, 95% CI: 0.70-0.77). Younger adult caregivers had equal or only slightly lower mortality than their controls, but after age 60, the difference increased markedly resulting in over 10% lower mortality in favor of the caregivers in the oldest age groups. Caregivers had lower mortality for all the causes of death studied, namely cardiovascular, cancer, neurological, external, respiratory, gastrointestinal and dementia than the controls. Of these, the lowest was the risk for dementia (subhazard ratio=0.29, 95%CI: 0.25-0.34).

Conclusions

Older family caregivers have lower mortality than the age-matched controls from the general population while younger caregivers have similar mortality to their peers. This age-dependent advantage in mortality is likely to reflect selection of healthier individuals into the family caregiver role.

Key messages

The difference in mortality between family caregivers and the age-matched general population varies considerably with age. Advantage in mortality observed in family caregiver studies is likely to reflect the selection of healthier individuals into the caregiver role, which underestimates the adverse effects of caregiving.

Neonatal outcomes among offspring of obese women diagnosed with gestational diabetes mellitus in early versus late pregnancy

BACKGROUND

Maternal metabolic derangements associated with early pregnancy gestational diabetes may affect the fetus differently compared with gestational diabetes diagnosed later in pregnancy. The aim of this observational study was to assess neonatal outcomes according to timing of gestational diabetes diagnosis in obese women.

METHODS

Women ≥18 years of age with a pre-pregnancy body mass index ≥30 kg/m2 were grouped according to the results of a 75 g 2-h oral glucose tolerance test performed at 13.1 weeks of gestation and repeated at 23.4 weeks if normal at first testing. The main outcomes were birthweight and large for gestational age.

RESULTS

Out of 361 women, 164 (45.4%) were diagnosed with gestational diabetes, 133 (81.1%) of them in early pregnancy. The mean offspring birthweight was 3673 g (standard deviation (SD) 589 g) in the early and 3710 g (SD 552 g) in the late gestational diabetes group. In a multivariate logit model, the odds ratio for large for gestational age was 2.01 (95% CI: 0.39-10.39) in early compared with late gestational diabetes.

CONCLUSIONS

We observed no statistically significant differences in neonatal outcomes according to timing of gestational diabetes diagnosis. In addition to lack of power, early treatment of hyperglycemia may partly explain the results.

Transgenerational effects of maternal obesity and gestational diabetes on offspring body composition and left ventricle mass: the Finnish Gestational Diabetes Prevention Study (RADIEL) 6-year follow-up

AIM

To investigate the influence of maternal adiposity and gestational diabetes on offspring body composition and left ventricle mass in early childhood.

METHODS

The observational follow-up study included 201 mother-child pairs, a sub-cohort from the Finnish Gestational Diabetes Prevention Study, who were recruited 6.1 ± 0.5 (mean ± SD) years postpartum, aiming for an equal number of mothers with and without gestational diabetes.

RESULTS

Maternal pre-pregnancy BMI (mean ± SD; 30.5 ± 5.6 kg/m² ) was associated with child body fat percentage [0.26 (95% CI; 0.08, 0.44)% increase in child body fat per 1 kg/m² increase in pre-pregnancy BMI of mothers with obesity] and was reflected in child BMI Z-score (mean ± SD; 0.45 ± 0.93). Left ventricle mass, left ventricle mass index and left ventricle mass Z-score were not associated with gestational diabetes, pre-pregnancy BMI or child body fat percentage. After adjusting for child sex, body fat percentage, systolic blood pressure, pre-pregnancy BMI and maternal lean body mass, left ventricle mass increased by 3.08 (95% CI; 2.25, 3.91) g for each 1 kg in child lean body mass.

CONCLUSIONS

Left ventricle mass at 6 years of age is determined predominantly by lean body mass. Maternal pre-gestational adiposity is reflected in child, but no direct association between left ventricle mass and child adiposity or evidence of left ventricle mass foetal programming related to gestational diabetes and maternal adiposity was observed in early childhood.

Impact of maternal income on the risk of gestational diabetes mellitus in primiparous women

AIMS

Findings concerning the impact of socio-economic status on the risk of gestational diabetes mellitus (GDM) are inconclusive and little is known about the simultaneous impact of income and educational attainment on the risk of GDM. This study aims to assess the impact of maternal prepregnancy income in combination with traditional GDM risk factors on the incidence of GDM in primiparous women.

METHODS

This is an observational cohort study including 5962 Finnish women aged ≥ 20 years from the city of Vantaa, Finland, who delivered for the first time between 2009 and 2015, excluding women with pre-existing diabetes mellitus. The Finnish Medical Birth Register, Finnish Tax Administration, Statistics Finland, Social Insurance Institution of Finland and patient healthcare records provided data for the study. We divided the study population according to five maternal income levels and four educational attainment levels.

RESULTS

Incidence of GDM decreased with increasing income level in primiparous women (P < 0.001 for linearity, adjusted for smoking, age, BMI and cohabiting status). In an adjusted two-way model, the relationship was significant for both income (P = 0.007) and education (P = 0.039), but there was no interaction between income and education (P = 0.52).

CONCLUSIONS

There was an inverse relationship between both maternal prepregnancy taxable income and educational attainment, and the risk of GDM in primiparous Finnish women.

Early life stress and frailty in old age: the Helsinki birth cohort study

BACKGROUND

Evidence suggests that early life stress (ELS) may extend its effect into adulthood and predispose an individual to adverse health outcomes. We investigated whether wartime parental separation, an indicator of severe ELS, would be associated with frailty in old age.

METHODS

Of the 972 participants belonging to the present sub-study of the Helsinki Birth Cohort Study, 117 (12.0%) had been evacuated abroad unaccompanied by their parents in childhood during World War II. Frailty was assessed at a mean age of 71 years according to Fried's criteria.

RESULTS

Thirteen frail men (4 separated and 9 non-separated) and 20 frail women (2 separated and 18 non-separated) were identified. Compared to the non-separated men, men who had been separated had an increased relative risk ratio (RRR) of frailty (age-adjusted RRR 3.93, 95% CI 1.02, 15.11) that persisted after adjusting for several confounders. No associations were observed among women (RRR 0.62; 95% CI 0.13, 2.94).

CONCLUSIONS

These preliminary results suggest that ELS might extend its effects not just into adulthood but also into old age, and secondly, that men may be more vulnerable to the long-term effects of ELS.

Early life determinants of frailty in old age: the Helsinki Birth Cohort Study

BACKGROUND

there is evidence suggesting that several chronic diseases have their origins in utero and that development taking place during sensitive periods may affect the aging process. We investigated whether early life determinants would be associated with frailty in old age.

METHODS

at a mean age of 71 years, 1,078 participants belonging to the Helsinki Birth Cohort Study were assessed for frailty according to the Fried frailty criteria. Early life measurements (birth weight, length, mother body mass index [BMI] and parity) were obtained from birth, child welfare and school health records. Multinomial regression analysis was used to assess the association between early life determinants and frailty in old age.

RESULTS

weight, length and BMI at birth were all inversely associated with frailty in old age. A 1 kg increase in birth weight was associated with a lower relative risk ratio (RRR) of frailty (age and sex-adjusted RRR = 0.40, 95% CI: 0.19, 0.82) compared to non-frailty. Associations persisted after adjusting for several confounding factors. Compared to cohort members in the upper middle class, those who as adults worked as manual workers or belonged to the lower middle class, were at an increased risk of frailty.

CONCLUSIONS

those who were small at birth were at an increased risk of developing frailty in old age, suggesting that frailty is at least partly programmed in early life. A less privileged socioeconomic status in adulthood was associated with an increased risk of frailty in old age.

Association between breastfeeding and better preserved cognitive ability in an elderly cohort of Finnish men

BACKGROUND

Being breastfed in infancy has been shown to benefit neurodevelopment. However, whether the benefits persist to old age remains unclear.

METHODS

We examined the associations between breastfeeding and its duration on cognitive ability in young adulthood and old age, and on aging-related cognitive change over five decades. In total, 931 men from the Helsinki Birth Cohort Study born in 1934-1944 in Finland took the Finnish Defence Forces Basic Intellectual Ability Test (total and verbal, arithmetic and visuospatial subtest scores) twice, at ages 20.2 and 67.9 years, and had data on breastfeeding (yes v. no) and its duration ('never breastfed', 'up to 3', '3 to 6' and '6 or more months'). Linear and mixed model regressions tested the associations.

RESULTS

At 20.2 years, breastfed men had higher cognitive ability total and visuospatial subtest scores [mean differences (MDs) ranged between 3.0-3.9, p values < 0.013], and its longer duration predicted higher cognitive ability total and arithmetic and visuospatial subtest scores (MDs ranged between 3.0 and 4.8, p values < 0.039). At 67.9 years, breastfed men had higher total cognitive ability and all subtest scores (MDs ranged between 2.6 and 3.4, p values < 0.044) and its longer duration predicted all cognitive ability scores (MDs ranged between 3.1 and 4.7, p values < 0.050). Verbal subtest scores decreased over five decades in men who were never breastfed or were breastfed for 3 months or less, and increased in those breastfed for longer than 3 months.

CONCLUSIONS

Neurodevelopmental advantages of breastfeeding and its longer duration persist into old age, and longer duration of breastfeeding may benefit aging-related change, particularly in verbal reasoning ability.

The effect of pre-pregnancy lifestyle counselling on food intakes and association between food intakes and gestational diabetes in high-risk women: results from a randomised controlled trial

BACKGROUND

Healthy diets before and during pregnancy have been suggested to reduce the risk of gestational diabetes (GDM). Several lifestyle intervention studies for pregnant women have reported dietary improvements after counselling. However, evidence concerning the effect of counselling initiated before pregnancy on diets is limited.

METHODS

This randomised controlled study explored whether pre-pregnancy lifestyle counselling influenced food intakes, as well as whether changes in food intakes were associated with GDM. The participants comprised 75 women with prior GDM and/or a body mass index ≥ 30 kg m^-2 . Women were randomised into a control or an intervention group, and their food intakes were followed from pre-pregnancy to early pregnancy using a food frequency questionnaire. The control and intervention groups were combined to assess the association between changes in food intakes and GDM. The diagnosis of GDM was based on a 75-g oral glucose tolerance test conducted in the first and second trimester of pregnancy.

RESULTS

Pre-pregnancy lifestyle counselling showed no major overall effect on food intakes. The intake of low-fat cheese increased significantly in women who did not develop GDM compared to women who did after adjusting for potential confounders (P = 0.028). This association was not observed for regular-fat cheese.

CONCLUSIONS

The findings obtained in the present study suggest that an increased intake of low-fat but not regular-fat cheese between pre-pregnancy and early pregnancy is associated with a lower risk of GDM in high-risk women.

GWAS meta-analysis reveals novel loci and genetic correlates for general cognitive function: a report from the COGENT consortium

This corrects the article DOI: 10.1038/mp.2016.244.

Childhood growth predicts higher bone mass and greater bone area in early old age: findings among a subgroup of women from the Helsinki Birth Cohort Study

We examined the associations between childhood growth and bone properties among women at early old age. Early growth in height predicted greater bone area and higher bone mineral mass. However, information on growth did not improve prediction of bone properties beyond that predicted by body size at early old age.

INTRODUCTION

We examined the associations between body size at birth and childhood growth with bone area, bone mineral content (BMC), and areal bone mineral density (aBMD) in early old age.

METHODS

A subgroup of women (n = 178, mean 60.4 years) from the Helsinki Birth Cohort Study, born 1934-1944, participated in dual-energy X-ray absorptiometry (DXA) measurements of the lumbar spine and hip. Height and weight at 0, 2, 7, and 11 years, obtained from health care records, were reconstructed into conditional variables representing growth velocity independent of earlier growth. Weight was adjusted for corresponding height. Linear regression models were adjusted for multiple confounders.

RESULTS

Birth length and growth in height before 7 years of age were positively associated with femoral neck area (p < 0.05) and growth in height at all age periods studied with spine bone area (p < 0.01). Growth in height before the age of 7 years was associated with BMC in the femoral neck (p < 0.01) and birth length and growth in height before the age of 7 years were associated with BMC in the spine (p < 0.05). After entering adult height into the models, nearly all associations disappeared. Weight gain during childhood was not associated with bone area or BMC, and aBMD was not associated with early growth.

CONCLUSIONS

Optimal growth in height in girls is important for obtaining larger skeleton and consequently higher bone mass. However, when predicting bone mineral mass among elderly women, information on early growth does not improve prediction beyond that predicted by current height and weight.

Adult height and glucose tolerance: a re-appraisal of the importance of body mass index

AIM

To study both the association between adult height and glucose regulation based on findings from a 75-g oral glucose tolerance test, and the combined effect of height and adiposity on glucose values.

METHODS

We conducted a population-based, cross-sectional study among apparently healthy people with high cardiovascular risk living in south-western Finland. The study included 2659 participants aged 45-70 years, who had at least one cardiovascular risk factor but no previously diagnosed diabetes or manifested cardiovascular disease. An oral glucose tolerance test was performed in all participants. Height and weight were measured and BMI was calculated. The participants were divided into five height groups based on normal distribution. For further analysis of the association between height and glucose concentrations the participants were divided into four BMI groups (<25.0 kg/m² ; 25-29.9 kg/m² ; 30-34.9 kg/m² ; ≥35 kg/m² ). Data were analysed using age-adjusted linear regression models.

RESULTS

Height was inversely associated with 2-h plasma glucose, but not with fasting plasma glucose concentration. No gender difference was observed. The 2-h plasma glucose values increased with an increase in BMI, so that height was inversely associated with 2-h plasma glucose in the three lowest BMI groups, but not in the highest BMI group (P=0.33).

CONCLUSIONS

Taller people had lower 2-h plasma glucose concentrations than shorter people, up to a BMI of 35 kg/m² . Adjustment for height and BMI is needed for accurate interpretation of oral glucose tolerance tests.

Costs of diabetes medication among male former elite athletes in later life

AIMS

Regular physical activity plays a major role, in both prevention and treatment of type 2 diabetes. Less is known whether vigorous physical activity during young adulthood is associated with costs of diabetes medication in later life. The aim of this study is to evaluate this question.

METHODS

The study population consisted of 1314 former elite-class athletes and 860 matched controls. The former athletes were divided into three groups based on their active career sport: endurance, mixed and power sports. Information on purchases of diabetes medication between 1995 and 2009 was obtained from the drug purchase register of the Finnish Social Insurance Institution.

RESULTS

The total cost of diabetes medication per person year was significantly lower among the former endurance (mean 81 € [95% CI 33-151 €]) and mixed group athletes (mean 272 € [95% CI 181-388 €]) compared with the controls (mean 376 € [95% CI 284-485 €]), (p < 0.001 and p = 0.045, respectively). Of the former endurance athletes, 0.4% used insulin, while 5.2% of the controls used insulin (p = 0.018).

CONCLUSIONS

A career as former endurance, sprint, jumper or team game athlete seems to reduce the costs of diabetes medication in later life.

GWAS meta-analysis reveals novel loci and genetic correlates for general cognitive function: a report from the COGENT consortium

The complex nature of human cognition has resulted in cognitive genomics lagging behind many other fields in terms of gene discovery using genome-wide association study (GWAS) methods. In an attempt to overcome these barriers, the current study utilized GWAS meta-analysis to examine the association of common genetic variation (~8M single-nucleotide polymorphisms (SNP) with minor allele frequency ⩾1%) to general cognitive function in a sample of 35 298 healthy individuals of European ancestry across 24 cohorts in the Cognitive Genomics Consortium (COGENT). In addition, we utilized individual SNP lookups and polygenic score analyses to identify genetic overlap with other relevant neurobehavioral phenotypes. Our primary GWAS meta-analysis identified two novel SNP loci (top SNPs: rs76114856 in the CENPO gene on chromosome 2 and rs6669072 near LOC105378853 on chromosome 1) associated with cognitive performance at the genome-wide significance level (P<5 × 10^-8). Gene-based analysis identified an additional three Bonferroni-corrected significant loci at chromosomes 17q21.31, 17p13.1 and 1p13.3. Altogether, common variation across the genome resulted in a conservatively estimated SNP heritability of 21.5% (s.e.=0.01%) for general cognitive function. Integration with prior GWAS of cognitive performance and educational attainment yielded several additional significant loci. Finally, we found robust polygenic correlations between cognitive performance and educational attainment, several psychiatric disorders, birth length/weight and smoking behavior, as well as a novel genetic association to the personality trait of openness. These data provide new insight into the genetics of neurocognitive function with relevance to understanding the pathophysiology of neuropsychiatric illness.

Mobility and muscle strength in male former elite endurance and power athletes aged 66-91 years

The aim of this cross-sectional study was to compare mobility and muscle strength in male former elite endurance and power athletes aged 66-91 years (n = 150; 50 men in both former elite athlete groups and in their control group). Agility, dynamic balance, walking speed, chair stand, self-rated balance confidence (ABC-scale), jumping height, and handgrip strength were assessed. Former elite power athletes had better agility performance time than the controls (age- and body mass index, BMI-adjusted mean difference -3.6 s; 95% CI -6.3, -0.8). Adjustment for current leisure time physical activity (LTPA) and prevalence of diseases made this difference non-significant (P = 0.214). The subjects in the power sports group jumped higher than the men in the control group (age- and BMI-adjusted mean differences for vertical squat jump, VSJ 4.4 cm; 95% CI 2.0, 6.8; for countermovement jump, CMJ 4.0 cm; 95% CI 1.7, 6.4). Taking current LTPA and chronic diseases for adjusting process did not improve explorative power of the model. No significant differences between the groups were found in the performances evaluating dynamic balance, walking speed, chair stand, ABC-scale, or handgrip strength. In conclusion, power athletes among the aged former elite sportsmen had greater explosive force production in their lower extremities than the men in the control group.

Childhood cognitive ability and body composition in adulthood

Background:

Childhood cognitive ability has been identified as a novel risk factor for adulthood overweight and obesity as assessed by adult body mass index (BMI). BMI does not, however, distinguish fat-free and metabolically harmful fat tissue. Hence, we examined the associations between childhood cognitive abilities and body fat percentage (BF%) in young adulthood.

Methods:

Participants of the Arvo Ylppö Longitudinal Study (n=816) underwent tests of general reasoning, visuomotor integration, verbal competence and language comprehension (M=100; s.d.=15) at the age of 56 months. At the age of 25 years, they underwent a clinical examination, including measurements of BF% by the InBody 3.0 eight-polar tactile electrode system, weight and height from which BMI (kg m⁻²) was calculated and waist circumference (cm).

Results:

After adjustments for sex, age and BMI-for-age s.d. score at 56 months, lower general reasoning and visuomotor integration in childhood predicted higher BMI (kg m⁻²) increase per s.d. unit decrease in cognitive ability (−0.32, 95% confidence interval −0.60,−0.05; −0.45, −0.75,−0.14, respectively) and waist circumference (cm) increase per s.d. unit decrease in cognitive ability (−0.84, −1.56,−0.11; −1.07,−1.88,−0.26, respectively) in adulthood. In addition, lower visuomotor integration predicted higher BF% per s.d. unit decrease in cognitive ability (−0.62,−1.14,−0.09). Associations between general reasoning and BMI/waist were attenuated when adjusted for smoking, alcohol consumption, intake of fruits and vegetables and physical activity in adulthood, and all associations, except for visuomotor integration and BMI, were attenuated when adjusted for parental and/or own attained education and/or birth weight.

Conclusions:

Of the measured childhood cognitive abilities, only lower visuomotor integration was associated with BF% in adulthood. This challenges the view that cognitive ability, at least when measured in early childhood, poses a risk for adiposity in adulthood, as characterized by higher BF%.

Common mental disorders in young adults born late-preterm

BACKGROUND

Results of adulthood mental health of those born late-preterm (34 + 0-36 + 6 weeks + days of gestation) are mixed and based on national registers. We examined if late-preterm birth was associated with a higher risk for common mental disorders in young adulthood when using a diagnostic interview, and if this risk decreased as gestational age increased.

METHOD

A total of 800 young adults (mean = 25.3, s.d. = 0.62 years), born 1985-1986, participated in a follow-up of the Arvo Ylppö Longitudinal Study. Common mental disorders (mood, anxiety and substance use disorders) during the past 12 months were defined using the Composite International Diagnostic Interview (Munich version). Gestational age was extracted from hospital birth records and categorized into early-preterm (<34 + 0, n = 37), late-preterm (34 + 0-36 + 6, n = 106), term (37 + 0-41 + 6, n = 617) and post-term (⩾42 + 0, n = 40).

RESULTS

Those born late-preterm and at term were at a similar risk for any common mental disorder [odds ratio (OR) 1.11, 95% confidence interval (CI) 0.67-1.84], for mood (OR 1.11, 95% CI 0.54-2.25), anxiety (OR 1.00, 95% CI 0.40-2.50) and substance use (OR 1.31, 95% CI 0.74-2.32) disorders, and co-morbidity of these disorders (p = 0.38). While the mental disorder risk decreased significantly as gestational age increased, the trend was driven by a higher risk in those born early-preterm.

CONCLUSIONS

Using a cohort born during the advanced neonatal and early childhood care, we found that not all individuals born preterm are at risk for common mental disorders in young adulthood - those born late-preterm are not, while those born early-preterm are at a higher risk. Available resources for prevention and intervention should be targeted towards the preterm group born the earliest.

Somatic, positive and negative domains of the Center for Epidemiological Studies Depression (CES-D) scale: a meta-analysis of genome-wide association studies

BACKGROUND

Major depressive disorder (MDD) is moderately heritable, however genome-wide association studies (GWAS) for MDD, as well as for related continuous outcomes, have not shown consistent results. Attempts to elucidate the genetic basis of MDD may be hindered by heterogeneity in diagnosis. The Center for Epidemiological Studies Depression (CES-D) scale provides a widely used tool for measuring depressive symptoms clustered in four different domains which can be combined together into a total score but also can be analysed as separate symptom domains.

METHOD

We performed a meta-analysis of GWAS of the CES-D symptom clusters. We recruited 12 cohorts with the 20- or 10-item CES-D scale (32 528 persons).

RESULTS

One single nucleotide polymorphism (SNP), rs713224, located near the brain-expressed melatonin receptor (MTNR1A) gene, was associated with the somatic complaints domain of depression symptoms, with borderline genome-wide significance (p discovery = 3.82 × 10-8). The SNP was analysed in an additional five cohorts comprising the replication sample (6813 persons). However, the association was not consistent among the replication sample (p discovery+replication = 1.10 × 10-6) with evidence of heterogeneity.

CONCLUSIONS

Despite the effort to harmonize the phenotypes across cohorts and participants, our study is still underpowered to detect consistent association for depression, even by means of symptom classification. On the contrary, the SNP-based heritability and co-heritability estimation results suggest that a very minor part of the variation could be captured by GWAS, explaining the reason of sparse findings.

Maternal adiposity and infancy growth predict later telomere length: a longitudinal cohort study

BACKGROUND/OBJECTIVES

Maternal overweight and obesity during pregnancy, and childhood growth patterns are risk factors influencing long-term health outcomes among the offspring. Furthermore, poor health condition has been associated with shorter leukocyte telomere length in adult subjects. We aimed to assess whether maternal adiposity during pregnancy and growth trajectory during infancy predict leukocyte telomere length (LTL) in later life.

SUBJECTS/METHODS

We studied a cohort of 1082 subjects belonging to the Helsinki Birth Cohort Study, born between 1934 and 1944. They underwent two clinical visits 10 years apart (2001-2004 and 2011-2013), during which LTL and anthropometrics were assessed. Birth records included birth weight, length, maternal body mass index (BMI) at the end of pregnancy. Serial measurements of height and weight from birth to 11 years were available.

RESULTS

Higher maternal BMI was associated with shorter LTL in elderly women (r=-0.102, P=0.024) but not in men. Also, in women but not in men shorter LTL and greater telomere shortening over a 10-year interval were predicted by higher weight at 12 months of age (P=0.008 and P=0.029, respectively), and higher weight gain during the first 12 months of life (P=0.008 and P=0.006, respectively), particularly between 6 and 9 months of age (P=0.002 for both LTL and LTL shortening rate). A correlation between younger age at adiposity rebound and shorter LTL at 60 years (P=0.022) was also found.

CONCLUSIONS

High maternal adiposity during pregnancy is associated with shorter LTL in elderly female offspring, but not in men. Moreover, higher weight and weight gain during the first year of life and younger age at adiposity rebound predict shorter LTL in older age in women, suggesting that rapid growth during the perinatal period accelerates cellular aging in late adulthood.

Association of Long-Term Dietary Fat Intake, Exercise, and Weight with Later Cognitive Function in the Finnish Diabetes Prevention Study

OBJECTIVES

To investigate associations of long-term nutrient intake, physical activity and obesity with later cognitive function among the participants in the Finnish Diabetes Prevention Study, in which a lifestyle intervention was successful in diabetes prevention.

DESIGN

An active lifestyle intervention phase during middle age (mean duration 4 years) and extended follow-up (additional 9 years) with annual lifestyle measurements, followed by an ancillary cognition assessment.

SETTING

5 research centers in Finland.

PARTICIPANTS

Of the 522 middle-aged, overweight participants with impaired glucose tolerance recruited to the study, 364 (70%) participated in the cognition assessment (mean age 68 years).

MEASUREMENTS

A cognitive assessment was executed with the CERAD test battery and the Trail Making Test A on average 13 years after baseline. Lifestyle measurements included annual clinical measurements, food records, and exercise questionnaires during both the intervention and follow-up phase.

RESULTS

Lower intake of total fat (p=0.021) and saturated fatty acids (p=0.010), and frequent physical activity (p=0.040) during the whole study period were associated with better cognitive performance. Higher BMI (p=0.012) and waist circumference (p=0.012) were also associated with worse performance, but weight reduction prior to the cognition assessment predicted worse performance as well (decrease vs. increase, p=0.008 for BMI and p=0.002 for waist).

CONCLUSIONS

Long-term dietary fat intake, BMI, and waist circumference have an inverse association with cognitive function in later life among people with IGT. However, decreases in BMI and waist prior to cognitive assessment are associated with worse cognitive performance, which could be explained by reverse causality.

GWAS for executive function and processing speed suggests involvement of the CADM2 gene

To identify common variants contributing to normal variation in two specific domains of cognitive functioning, we conducted a genome-wide association study (GWAS) of executive functioning and information processing speed in non-demented older adults from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) consortium. Neuropsychological testing was available for 5429-32,070 subjects of European ancestry aged 45 years or older, free of dementia and clinical stroke at the time of cognitive testing from 20 cohorts in the discovery phase. We analyzed performance on the Trail Making Test parts A and B, the Letter Digit Substitution Test (LDST), the Digit Symbol Substitution Task (DSST), semantic and phonemic fluency tests, and the Stroop Color and Word Test. Replication was sought in 1311-21860 subjects from 20 independent cohorts. A significant association was observed in the discovery cohorts for the single-nucleotide polymorphism (SNP) rs17518584 (discovery P-value=3.12 × 10(-8)) and in the joint discovery and replication meta-analysis (P-value=3.28 × 10(-9) after adjustment for age, gender and education) in an intron of the gene cell adhesion molecule 2 (CADM2) for performance on the LDST/DSST. Rs17518584 is located about 170 kb upstream of the transcription start site of the major transcript for the CADM2 gene, but is within an intron of a variant transcript that includes an alternative first exon. The variant is associated with expression of CADM2 in the cingulate cortex (P-value=4 × 10(-4)). The protein encoded by CADM2 is involved in glutamate signaling (P-value=7.22 × 10(-15)), gamma-aminobutyric acid (GABA) transport (P-value=1.36 × 10(-11)) and neuron cell-cell adhesion (P-value=1.48 × 10(-13)). Our findings suggest that genetic variation in the CADM2 gene is associated with individual differences in information processing speed.

Insulin therapy in the elderly with type 2 diabetes

Type 2 diabetes (T2D) is a progressive disorder and therefore many elderly people with T2D will require insulin therapy in order to reach treatment targets and to optimize quality of life. It is commonly assumed that insulin is underutilized in elderly T2 diabetics because of fear that it is too complicated to use. With the use of long-acting insulin analogues it has become much easier to use insulin in elderly patients as once daily pen injections. When basal insulin treatment is initiated in T2D it is often added to the oral medication. The use of basal insulin analogues (e.g. detemir and glargine) with relatively little peaking effects has made insulin therapy in elderly subjects a relatively straightforward process. Newer insulin analogues are also discussed. The use of prandial insulin in addition to basal insulin and use of premixed insulin analogues is also discussed and illustrated with patient cases. Avoidance of hypoglycemia is an important factor to consider when choosing therapeutic agents for elderly T2D diabetics. This is certainly also true when establishing glycemic goals. Therefore insulin must be used with caution and wisely and the motto "start low and go slow" is a good principle. Basal insulin therapy in combination with oral drugs, most often metformin ‑ is the most convenient initial regimen. However, all next steps, from one to two or even more daily injections in elderly T2D subjects should be considered carefully.

Trajectories of body mass index amongst children who develop type 2 diabetes as adults

OBJECTIVE

Type 2 diabetes (T2D) is a heterogeneous disorder. The aim of this study was to examine the trajectories of childhood growth associated with T2D.

DESIGN AND SUBJECTS

A total of 13 345 individuals born in Helsinki, Finland between 1934 and 1944 were included in the study. The participants' growth had been recorded in detail during childhood, and 11.7% (n = 1558) had been diagnosed with T2D. We divided the cohort around the median body mass index (BMI) at 11 years. Body composition and glucose tolerance were assessed in a clinical subsample (n = 2003) in adulthood.

RESULTS

Two pathways of growth were associated with T2D. Both began with low weight and BMI at birth. In one, persistent low BMI through infancy was followed by a rapid increase in BMI in childhood. Amongst individuals with a BMI at 11 years above the median value, the odds ratio for T2D associated with a one z-score increase in BMI between 2 and 11 years was 1.31 (95% confidence interval 1.21-1.42, P < 0.001). In the other pathway, low BMI at birth, accompanied by short length at birth, was followed by low BMI in childhood. Most women who developed diabetes followed this trajectory; they developed T2D at a lower BMI and lower fat percentage than women with a BMI above the median at 11 years of age.

CONCLUSIONS

Two pathways of early growth trigger T2D. Low fat deposition leading to thinness at birth and during infancy results in fat acquisition during childhood. Reduced linear growth leading to short length at birth is associated with lower body fat percentage in adulthood but increased risk of developing diabetes.

Markers of cholesterol metabolism as biomarkers in predicting diabetes in the Finnish Diabetes Prevention Study

BACKGROUND AND AIMS

We examined the effect of serum markers of cholesterol synthesis and absorption on the incidence of type 2 diabetes (T2D) in the randomized Finnish Diabetes Prevention Study (DPS). We also explored a possible interaction of ABCG8 rs4299376 on sterol levels and lifestyle intervention.

METHODS AND RESULTS

We conducted a prospective cohort study including overweight, middle-aged people with impaired glucose tolerance at baseline who participated in the randomized DPS. The primary outcome of the DPS was the diagnosis of T2D based on repeated oral glucose tolerance tests (OGTTs). After active intervention (median of four years, 1994-2001), non-T2D participants were further followed until T2D diagnosis, dropout or the end of 2009. Of these, 340 participants who had β-sitosterol, campesterol, lathosterol and desmosterol measured by gas chromatography-mass spectrometry during the active four-year follow-up and who were not using cholesterol lowering medications were analysed. Surrogate indexes of insulin sensitivity (IS) and secretion were calculated from an OGTT. In adjusted models, plant sterols during the four-year follow-up were associated with lower T2D incidence during the extended eight-year follow-up (HR for 1-SD change in β-sitosterol and campesterol: 0.76 [0.63-0.92], and 0.81 [0.67-0.99], respectively). Lathosterol levels were associated with higher T2D incidence (HR: 1.35 [1.13-1.62]). These associations, though, were not independent of IS. There was an interaction between rs4299376 and study group on β-sitosterol (p = 0.001) and campesterol (p = 0.004) levels during the follow-up.

CONCLUSIONS

Markers of low absorption and high synthesis of cholesterol were associated with the risk of developing T2D, mostly ascribed to IS.

Late preterm birth, post-term birth, and abnormal fetal growth as risk factors for severe mental disorders from early to late adulthood

BACKGROUND

Late preterm births constitute the majority of preterm births. However, most evidence suggesting that preterm birth predicts the risk of mental disorders comes from studies on earlier preterm births. We examined if late preterm birth predicts the risks of severe mental disorders from early to late adulthood. We also studied whether adulthood mental disorders are associated with post-term birth or with being born small (SGA) or large (LGA) for gestational age, which have been previously associated with psychopathology risk in younger ages.

METHOD

Of 12 597 Helsinki Birth Cohort Study participants, born 1934-1944, 664 were born late preterm, 1221 post-term, 287 SGA, and 301 LGA. The diagnoses of mental disorders were identified from national hospital discharge and cause of death registers from 1969 to 2010. In total, 1660 (13.2%) participants had severe mental disorders.

RESULTS

Individuals born late preterm did not differ from term-born individuals in their risk of any severe mental disorder. However, men born late preterm had a significantly increased risk of suicide. Post-term birth predicted significantly increased risks of any mental disorder in general and particularly of substance use and anxiety disorders. Individuals born SGA had significantly increased risks of any mental and substance use disorders. Women born LGA had an increased risk of psychotic disorders.

CONCLUSIONS

Although men born late preterm had an increased suicide risk, late preterm birth did not exert widespread effects on adult psychopathology. In contrast, the risks of severe mental disorders across adulthood were increased among individuals born SGA and individuals born post-term.

Is the adiposity-associated FTO gene variant related to all-cause mortality independent of adiposity? Meta-analysis of data from 169,551 Caucasian adults

Previously, a single nucleotide polymorphism (SNP), rs9939609, in the FTO gene showed a much stronger association with all-cause mortality than expected from its association with body mass index (BMI), body fat mass index (FMI) and waist circumference (WC). This finding implies that the SNP has strong pleiotropic effects on adiposity and adiposity-independent pathological pathways that leads to increased mortality. To investigate this further, we conducted a meta-analysis of similar data from 34 longitudinal studies including 169,551 adult Caucasians among whom 27,100 died during follow-up. Linear regression showed that the minor allele of the FTO SNP was associated with greater BMI (n = 169,551; 0.32 kg m(-2) ; 95% CI 0.28-0.32, P < 1 × 10(-32) ), WC (n = 152,631; 0.76 cm; 0.68-0.84, P < 1 × 10(-32) ) and FMI (n = 48,192; 0.17 kg m(-2) ; 0.13-0.22, P = 1.0 × 10(-13) ). Cox proportional hazard regression analyses for mortality showed that the hazards ratio (HR) for the minor allele of the FTO SNPs was 1.02 (1.00-1.04, P = 0.097), but the apparent excess risk was eliminated after adjustment for BMI and WC (HR: 1.00; 0.98-1.03, P = 0.662) and for FMI (HR: 1.00; 0.96-1.04, P = 0.932). In conclusion, this study does not support that the FTO SNP is associated with all-cause mortality independently of the adiposity phenotypes.

Former male elite athletes have better metabolic health in late life than their controls

Elite-class athletes have longer life expectancy and lower risk for chronic noncommunicable diseases possibly because of physically active and healthier lifestyle. In this study, we assessed former male Finnish elite-class athletes' (n = 392) and their matched controls' (n = 207) body composition, and risk for the metabolic syndrome (MS) and nonalcoholic fatty liver disease (NAFLD) in later life. Compared with the controls, the former athletes had lower body fat percentage (24.8% vs 26.0%, P = 0.021), lower risk for MS [odds ratio (OR) 0.57, 95% confidence interval (CI) 0.40-0.81], and NAFLD (OR 0.61, 95% CI 0.42-0.88). High volume of current leisure-time physical activity (LTPA) was associated with lower body fat percentage (P for trend < 0.001). When current volume of LTPA increased 1 MET h/week, the risk of MS and NAFLD decreased (OR 0.99, 95% CI 0.98-0.99 and OR 0.97, 95% CI 0.96-0.98, respectively). Although a career as an elite-class athlete during young adulthood may help to protect from developing metabolic syndrome, present exercise levels and volume of LTPA seem equally important as well.

Genetic contributions to variation in general cognitive function: a meta-analysis of genome-wide association studies in the CHARGE consortium (N=53949)

General cognitive function is substantially heritable across the human life course from adolescence to old age. We investigated the genetic contribution to variation in this important, health- and well-being-related trait in middle-aged and older adults. We conducted a meta-analysis of genome-wide association studies of 31 cohorts (N=53,949) in which the participants had undertaken multiple, diverse cognitive tests. A general cognitive function phenotype was tested for, and created in each cohort by principal component analysis. We report 13 genome-wide significant single-nucleotide polymorphism (SNP) associations in three genomic regions, 6q16.1, 14q12 and 19q13.32 (best SNP and closest gene, respectively: rs10457441, P=3.93 × 10(-9), MIR2113; rs17522122, P=2.55 × 10(-8), AKAP6; rs10119, P=5.67 × 10(-9), APOE/TOMM40). We report one gene-based significant association with the HMGN1 gene located on chromosome 21 (P=1 × 10(-6)). These genes have previously been associated with neuropsychiatric phenotypes. Meta-analysis results are consistent with a polygenic model of inheritance. To estimate SNP-based heritability, the genome-wide complex trait analysis procedure was applied to two large cohorts, the Atherosclerosis Risk in Communities Study (N=6617) and the Health and Retirement Study (N=5976). The proportion of phenotypic variation accounted for by all genotyped common SNPs was 29% (s.e.=5%) and 28% (s.e.=7%), respectively. Using polygenic prediction analysis, ~1.2% of the variance in general cognitive function was predicted in the Generation Scotland cohort (N=5487; P=1.5 × 10(-17)). In hypothesis-driven tests, there was significant association between general cognitive function and four genes previously associated with Alzheimer's disease: TOMM40, APOE, ABCG1 and MEF2C.

The healthy Nordic diet and incidence of Type 2 Diabetes--10-year follow-up

Studies have shown that a diet of healthy foods typical of Nordic countries has a beneficial effect on risk factors for Type 2 Diabetes (T2D), such as obesity and low-grade inflammation. However, longitudinal epidemiological studies examining the association between the healthy Nordic diet and T2D are lacking.

Small head circumference at birth and early age at adiposity rebound

AIMS

The adiposity rebound is the age in childhood when body mass index is at a minimum before increasing again. The age at rebound is highly variable. An early age is associated with increased obesity in later childhood and adult life. We have reported that an early rebound is predicted by low weight gain between birth and 1 year of age and resulting low body mass index at 1 year. Here, we examine whether age at adiposity rebound is determined by influences during infancy or is a consequence of foetal growth. Our hypothesis was that measurements of body size at birth are related to age at adiposity rebound.

METHODS

Longitudinal study of 2877 children born in Helsinki, Finland, during 1934-1944.

RESULTS

Early age at adiposity rebound was associated with small head circumference and biparietal diameter at birth, but not with other measurements of body size at birth. The mean age at adiposity rebound rose from 5.8 years in babies with a head circumference of ≤33 cm to 6.2 in babies with a head circumference of >36 cm (P for trend = 0.007). The association between thinness in infancy and early rebound became apparent at 6 months of age. It was not associated with adverse living conditions. In a simultaneous regression, small head circumference at birth, high mother's body mass index and tall maternal stature each had statistically significant trends with early adiposity rebound (P = 0.002, <0.001, 0.004).

CONCLUSION

We hypothesize that the small head size at birth that preceded an early adiposity rebound was the result of inability to sustain a rapid intra-uterine growth trajectory initiated in association with large maternal body size. This was followed by catch-up growth in infancy, and we hypothesize that this depleted the infant's fat stores.

Fish processing facilities: new challenge to marine biosecurity in Canada

The transmission of pathogens is a common consequence of animal food production. Marine salmon farms and their processing facilities can serve as sources of virulent fish pathogens; our study is the first to confirm the broadcast of a live fish pathogen from a farmed salmon processing facility into the marine waters of Canada's Pacific coast. We found live salmon lice Lepeophtheirus salmonis, mucus, and fish tissue in effluent from the processing facility. Sea lice transmitted from this source may pose a threat to wild salmon populations, and the release of untreated offal, including blood water, is of considerable concern. Further research is needed to quantify the extent to which processing facilities release sea lice and to determine whether more virulent fish pathogens are present in effluent. These data underscore the need for fish farming nations to develop mandatory biosecurity programs to ensure that farmed salmon processing facilities will prevent the broadcast of infectious fish pathogens into wild fish habitat.

Improved lifestyle and decreased diabetes risk over 13 years: long-term follow-up of the randomised Finnish Diabetes Prevention Study (DPS)

AIMS/HYPOTHESIS

This study aimed to determine whether lifestyle intervention lasting for 4 years affected diabetes incidence, body weight, glycaemia or lifestyle over 13 years among individuals at high risk of type 2 diabetes.

METHODS

Overweight, middle-aged men (n = 172) and women (n = 350) with impaired glucose tolerance were randomised in 1993-1998 to an intensive lifestyle intervention group (n = 265), aiming at weight reduction, dietary modification and increased physical activity, or to a control group (n = 257) that received general lifestyle information. The primary outcome was a diagnosis of diabetes based on annual OGTTs. Secondary outcomes included changes in body weight, glycaemia, physical activity and diet. After active intervention (median 4 years, range 1-6 years), participants still free of diabetes and willing to continue their participation (200 in the intervention group and 166 in the control group) were further followed until diabetes diagnosis, dropout or the end of 2009, with a median total follow-up of 9 years and a time span of 13 years from baseline.

RESULTS

During the total follow-up the adjusted HR for diabetes (intervention group vs control group) was 0.614 (95% CI 0.478, 0.789; p < 0.001). The corresponding HR during the post-intervention follow-up was 0.672 (95% CI 0.477, 0.947; p = 0.023). The former intervention group participants sustained lower absolute levels of body weight, fasting and 2 h plasma glucose and a healthier diet. Adherence to lifestyle changes during the intervention period predicted greater risk reduction during the total follow-up.

CONCLUSIONS/INTERPRETATION

Lifestyle intervention in people at high risk of type 2 diabetes induces sustaining lifestyle change and results in long-term prevention of progression to type 2 diabetes.

Effect of a common variant of the PCSK2 gene on reduced insulin secretion

AIM/HYPOTHESIS

Individuals at risk of developing type 2 diabetes show a progressive decline in insulin secretion and increased insulin resistance over time. However, inability of the beta cells to compensate for the increased insulin resistance represents a key defect leading to overt type 2 diabetes. The aims of the present study were to replicate the association between genetic variants of the PCSK2 gene and insulin secretion, and to explore the effect on risk of type 2 diabetes.

METHODS

Replication of PCSK2 variants against insulin secretion included 7,682 non-diabetic Scandinavian individuals. Insulin secretion was measured as the corrected insulin response or disposition index, i.e. insulin secretion adjusted for the degree of insulin resistance. Risk of type 2 diabetes was studied in 28,287 Scandinavian individuals.

RESULTS

The C-allele of PCSK2 rs2208203 was associated with reduced insulin secretion measured as the corrected insulin response (n = 8,151; β = -0.112, p = 1.3 × 10(-6)) as well as disposition index (n = 8,078, β = -0.128, p = 1.6 × 10(-7)). The variant was also associated with lower fasting glucagon levels (β = -0.084, p = 0.005) in non-diabetic individuals with a fasting plasma glucose of over 5.5 mmol/l. In human pancreatic islets, PCSK2 expression correlated negatively with HbA(1c) (n = 133, r = -0.196, p = 0.038), and showed a tendency to be lower in hyperglycaemic (HbA(1c) ≥6.0% or type 2 diabetes; n = 47, p = 0.13) than normoglycaemic (HbA(1c) >6.0%; n = 66) donors. The presence of the PCSK2 rs2208203 risk allele did not influence gene expression, nor did it show an apparent risk in terms of type 2 diabetes.

CONCLUSIONS/INTERPRETATION

A variant of the PCSK2 gene was associated with reduced glucose-stimulated insulin secretion, but also with lower glucagon levels, which could potentially counteract the effects of decreased insulin secretion on the risk of type 2 diabetes.

Unfavorable influence of structured exercise program on total leisure-time physical activity

In randomized controlled trials (RCTs), with customized structured physical exercise activity (SPEA) interventions, the dose of leisure-time physical activity (LTPA) should exceed the LTPA dose of the nonexercising control (C) group. This increase is required to substantiate health improvements achievable by exercise. We aimed to compare the dose of SPEA, LTPA, and total LTPA (SPEA + LTPA) between a randomized Nordic walking (NW) group, a power-type resistance training (RT) group, and a C group during a 12-week exercise intervention in obese middle-aged men (n = 144) with impaired glucose regulation. The dose of physical activity was measured with diaries using metabolic equivalents. No significant difference (P > 0.107) between the groups was found in volume of total LTPA. The volume of LTPA was, however, significantly higher (P < 0.050) in the C group than in the NW group, but not compared with the RT group. These results indicate that structured exercise does not automatically increase the total LTPA level, possibly, as a result of compensation of LTPA with structured exercise or spontaneous activation of the C group. Thus, the dose of total LTPA and the possible changes in spontaneous LTPA should be taken into account when implementing a RCT design with exercise intervention.

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.

Neurocognitive abilities in young adults with very low birth weight

OBJECTIVE

Although severely preterm birth has been associated with impaired neurocognitive abilities in children, follow-up studies in adulthood are scarce. We set out to study whether adults born with very low birth weight (VLBW) (<1,500 g), either small for gestational age (SGA) (birth weight ≤-2 SD) or appropriate for gestational age (AGA), differ in a range of neurocognitive abilities and academic performance from adults born at term and not SGA.

METHODS

As part of the Helsinki Study of Very Low Birth Weight Adults, 103 VLBW (37 SGA) and 105 term-born control adults (mean age 25.0, range 21.4-29.7 years) without major neurosensory impairments participated in the follow-up study in 2007-2008. The test battery included measures of general cognitive ability as well as executive functioning and related abilities. Academic performance was self-reported.

RESULTS

With adjustment for sex and age, the VLBW group scored lower or performed slower than the control group in some indices of all tests (these mean differences ranged from 0.3 to 0.5 SD units, p ≤ 0.03) and they had received remedial education at school more frequently; however, no differences existed in self-reported academic performance. The differences were evident in both VLBW-SGA and VLBW-AGA groups. Further covariate adjustments for parental education, current head circumference, and head circumference at birth and, in tests of executive functioning and related abilities, adjustment for IQ estimate had minor effects on the results.

CONCLUSIONS

In comparison with control adults, VLBW adults scored lower on several neurocognitive tests. Poorer neurocognitive performance is associated with VLBW irrespective of the intrauterine growth pattern.

A common variant upstream of the PAX6 gene influences islet function in man

AIMS/HYPOTHESIS

Impaired glucose tolerance and impaired insulin secretion have been reported in families with PAX6 mutations and it is suggested that they result from defective proinsulin processing due to lack of prohormone convertase 1/3, encoded by PCSK1. We investigated whether a common PAX6 variant would mimic these findings and explored in detail its effect on islet function in man.

METHODS

A PAX6 candidate single nucleotide polymorphism (rs685428) was associated with fasting insulin levels in the Diabetes Genetics Initiative genome-wide association study. We explored its potential association with glucose tolerance and insulin processing and secretion in three Scandinavian cohorts (N = 8,897 individuals). In addition, insulin secretion and the expression of PAX6 and transcriptional target genes were studied in human pancreatic islets.

RESULTS

rs685428 G allele carriers had lower islet mRNA expression of PAX6 (p = 0.01) and PCSK1 (p = 0.001) than AA homozygotes. The G allele was associated with increased fasting insulin (p (replication) = 0.02, p (all) = 0.0008) and HOMA-insulin resistance (p (replication) = 0.02, p (all) = 0.001) as well as a lower fasting proinsulin/insulin ratio (p (all) = 0.008) and lower fasting glucagon (p = 0.04) and gastric inhibitory peptide (GIP) (p = 0.05) concentrations. Arginine-stimulated (p = 0.02) insulin secretion was reduced in vivo, which was further reflected by a reduction of glucose- and potassium-stimulated insulin secretion (p = 0.002 and p = 0.04, respectively) in human islets in vitro.

CONCLUSIONS/INTERPRETATION

A common variant in PAX6 is associated with reduced PAX6 and PCSK1 expression in human islets and reduced insulin response, as well as decreased glucagon and GIP concentrations and decreased insulin sensitivity. These findings emphasise the central role of PAX6 in the regulation of islet function and glucose metabolism in man.

The lifespan of men and the shape of their placental surface at birth

BACKGROUND

Tall men generally lead longer lives than short men. Within the Helsinki Birth Cohort, however, there is a group of boys among whom being tall when they entered school was associated with reduced lifespan. These boys had birthweights and maternal heights above the median for the cohort; but they tended to be lighter at birth than their mother's body mass index (weight/height(2)) in pregnancy predicted. We suggested that, while they had grown rapidly in utero, their growth had faltered at some point; and their tallness at age seven was the result of a resumption during infancy of their rapid growth trajectory. We here examine the size and shape of their placentas at birth to gain further insight into their path of fetal growth.

METHODS

We examined all cause mortality in the 1217 men who had birthweights and maternal heights above the median for the cohort. Their birth measurements included placental weight and the length and breadth of the placental surface.

RESULTS

Shorter length of the placental surface was associated with increased mortality (p = 0.002). There was no similar trend with the breadth. Mortality rose as the difference between the length and breadth decreased, that is as the surface became rounder. The hazard ratio was 1.10 (1.03-1.18, p = 0.007) for every cm decrease in the difference. Among men with a round placental surface (length-breadth difference 2 cm or less) increased mortality was associated with lower birthweight (p = 0.03 or 0.005 allowing for mother's body mass index) and shorter gestation, but not with lower head circumference or length.

CONCLUSION

Reduced lifespan among men is associated with a particular path of early growth. After rapid growth in early gestation, associated with tall maternal stature, soft tissue growth falters in mid-gestation. Rapid growth resumes in late gestation and continues through infancy.

Meta-analysis of genome-wide association studies identifies common variants in CTNNA2 associated with excitement-seeking

The tendency to seek stimulating activities and intense sensations define excitement-seeking, a personality trait akin to some aspects of sensation-seeking. This trait is a central feature of extraversion and is a component of the multifaceted impulsivity construct. Those who score high on measures of excitement-seeking are more likely to smoke, use other drugs, gamble, drive recklessly, have unsafe/unprotected sex and engage in other risky behaviors of clinical and social relevance. To identify common genetic variants associated with the Excitement-Seeking scale of the Revised NEO Personality Inventory, we performed genome-wide association studies in six samples of European ancestry (N=7860), and combined the results in a meta-analysis. We identified a genome-wide significant association between the Excitement-Seeking scale and rs7600563 (P=2 × 10(-8)). This single-nucleotide polymorphism maps within the catenin cadherin-associated protein, alpha 2 (CTNNA2) gene, which encodes for a brain-expressed α-catenin critical for synaptic contact. The effect of rs7600563 was in the same direction in all six samples, but did not replicate in additional samples (N=5105). The results provide insight into the genetics of excitement-seeking and risk-taking, and are relevant to hyperactivity, substance use, antisocial and bipolar disorders.

Association of the FTO gene variant (rs9939609) with cardiovascular disease in men with abnormal glucose metabolism--the Finnish Diabetes Prevention Study

BACKGROUND AND AIM

The common single nucleotide polymorphism (SNP) in the FTO (fat mass and obesity associated) gene has been consistently associated with an increased risk of obesity. We investigated whether the SNP rs9939609 (T/A) of the FTO is associated with risk factors of cardiovascular diseases (CVD), including serum levels of C - reactive protein (CRP), the chemokine RANTES (Regulated on Activation, Normal T Cell Expressed and Secreted; CCL5), and serum and lipoprotein lipids in the Finnish Diabetes Prevention Study (DPS). Furthermore, we examined whether the rs9939609 increased the CVD risk in the DPS and if these results could be replicated in a larger cross-sectional population-based random sample of Finnish men (the METSIM).

METHODS AND RESULTS

In the DPS, altogether 490 (BMI≥25kg/m(2)) subjects with impaired glucose tolerance were genotyped for rs9939609. Cardiovascular morbidity and mortality data were collected during the median follow-up of 10.2 years. The replication study was a population-based cross-sectional study of 6214 men. In the DPS, the AA genotype of rs9939609 was associated, independently of BMI, with increased RANTES (p=0.002) and decreased HDL cholesterol concentrations (p=0.007) in men. During the follow-up, the AA genotype was associated with an adjusted 2.09-fold risk (95% CI 1.17-3.73, p=0.013) of CVD in men. In the METSIM Study, the association with a history of myocardial infarction was replicated in the subgroup of men with type 2 diabetes.

CONCLUSION

We suggest that the variation in the FTO gene may contribute to the development of CVD in men with an abnormal glucose metabolism.

Growth in childhood predicts hip fracture risk in later life

The incidence of hip fracture was estimated in 6,370 women born in Helsinki between 1934 and 1944. Women in the lowest quarter of adiposity gain had an 8.2-fold increase in hip fracture risk compared with those in the highest quarter (p < 0.001). These data point to a relationship between childhood growth and fracture risk during later life.

INTRODUCTION

Previous findings show that discordance between childhood increase in height and weight is associated with an increased risk of osteoporotic fractures during later life.

METHODS

We studied 6,370 women born in Helsinki between 1934 and 1944. Each woman's birth weight and length at birth was recorded, as well as her height and weight through childhood. We identified the occurrence of hip fracture through the National Finnish Hospital discharge register.

RESULTS

There were 49 hip fractures in the 6,370 women over 187,238 person-years of follow-up. Hip fracture was associated with increasing Z-scores for height between 1 and 12 years, not matched by a corresponding increase in weight. Therefore, reduction in the Z-score for body mass index was associated with increased risk of hip fracture. Women in the lowest quarter of change in Z-scores for body mass index had an 8.2-fold increase in hip fracture risk (95% CI 1.9 to 35), compared with those in the highest quarter (p < 0.001).

CONCLUSION

Thinness in childhood is a risk factor for hip fracture in later life. This could be a direct effect of low fat mass on bone mineralization, or represent the influence of altered timing of pubertal maturation.

HbA(1c) in diagnosing and predicting Type 2 diabetes in impaired glucose tolerance: the Finnish Diabetes Prevention Study

AIMS

We analysed the Finnish Diabetes Prevention Study data in order to evaluate how the new HbA(1c) -based criterion compares with the oral glucose tolerance test in diagnosing Type 2 diabetes among high-risk individuals during a prospective average follow-up of 4 years.

METHODS

In the Diabetes Prevention Study, 172 men and 350 women who were overweight and had impaired glucose tolerance at baseline were randomized into an intensive lifestyle intervention or a control group. The oral glucose tolerance test and HbA(1c) measurements were performed annually until the diagnosis of diabetes using the World Health Organization 1985 criteria.

RESULTS

The sensitivity of the HbA(1c) ≥ 6.5% (≥ 48 mmol/mol) as a diagnostic criterion for Type 2 diabetes was 35% (95% CI 24%, 47%) in women and 47% (95% CI 31%, 64%) in men compared with diagnosis based on two consecutive oral glucose tolerance tests. The corresponding sensitivities for HbA(1c) ≥ 6.0% (≥ 42 mmol/mol) were 67% (95% CI 55%, 77%) and 68% (95% CI 51%, 82%). The participants with HbA(1c) ≥ 6.5% (≥ 48 mmol/mol) and diabetes based on the oral glucose tolerance test were more obese and had higher fasting glucose and 2-h glucose concentrations than those who had a diabetic oral glucose tolerance test but HbA(1c) < 6.5% (< 48 mmol/mol). There were no differences in the predictive performance of baseline fasting glucose, oral glucose tolerance test and HbA(1c) .

CONCLUSIONS

Of those with diabetes diagnosis based on two oral glucose tolerance tests during the Diabetes Prevention Study follow-up, 60% would have remained undiagnosed if diagnosis had been based on HbA(1c) ≥ 6.5% (≥ 48 mmol/mol) criterion.

A family history of diabetes is associated with reduced physical fitness in the Prevalence, Prediction and Prevention of Diabetes (PPP)-Botnia study

AIMS/HYPOTHESIS

We studied the impact of a family history of type 2 diabetes on physical fitness, lifestyle factors and diabetes-related metabolic factors.

METHODS

The Prevalence, Prediction and Prevention of Diabetes (PPP)-Botnia study is a population-based study in Western Finland, which includes a random sample of 5,208 individuals aged 18 to 75 years identified through the national Finnish Population Registry. Physical activity, dietary habits and family history of type 2 diabetes were assessed by questionnaires and physical fitness by a validated 2 km walking test. Insulin secretion and action were assessed based upon OGTT measurements of insulin and glucose.

RESULTS

A family history of type 2 diabetes was associated with a 2.4-fold risk of diabetes and lower physical fitness (maximal aerobic capacity 29.2 +/- 7.2 vs 32.1 +/- 7.0, p = 0.01) despite having similar reported physical activity to that of individuals with no family history. The same individuals also had reduced insulin secretion adjusted for insulin resistance, i.e. disposition index (p < 0.001) despite having higher BMI (27.4 +/- 4.6 vs 26.0 +/- 4.3 kg/m(2), p < 0.001).

CONCLUSIONS/INTERPRETATION

Individuals with a family history of type 2 diabetes are characterised by lower physical fitness, which cannot solely be explained by lower physical activity. They also have an impaired capacity of beta cells to compensate for an increase in insulin resistance imposed by an increase in BMI. These defects should be important targets for interventions aiming at preventing type 2 diabetes in individuals with inherited susceptibility to the disease.