Life course body mass index and risk of knee osteoarthritis at the age of 53 years: evidence from the 1946 British birth cohort study

Introduction

The authors examined how body mass index (BMI) across life is linked to the risk of midlife knee osteoarthritis (OA), testing whether prolonged exposure to high BMI or high BMI at a particular period has the greatest influence on the risk of knee OA.

Methods

A population-based British birth cohort of 3035 men and women underwent clinical examination for knee OA at age 53 years.Heights and weights were measured 10 times from 2 to 53 years. Analyses were stratified by gender and adjusted for occupation and activity levels.

Results

The prevalence of knee OA was higher in women than in men (12.9% (n=194) vs 7.4% (n=108)). In men, the association between BMI and later knee OA was evident at 20 years (p=0.038) and remained until 53 years (OR per z-score 1.38 (95% CI 1.11 to 1.71)). In women, there was evidence for an association at 15 years (p=0.003); at 53 years, the OR was 1.89 (95% CI 1.59 to 2.24) per z-score increase in BMI. Changes in BMI from childhood in women and from adolescence in men were also positively associated with knee OA. A structured modelling approach to disentange the way in which BMI is linked to knee OA suggested that prolonged exposure to high BMI throughout adulthood carried the highest risk and that there was no additional risk conferred from adolescence once adult BMI had been accounted for.

Conclusion

This study suggests that the risk of knee OA accumulates from exposure to a high BMI through adulthood.

Factors associated with symptoms of anxiety and depression in five cohorts of community-based older people: the HALCyon (Healthy Ageing across the Life Course) Programme

BACKGROUND

Symptoms of anxiety and depression are common in older people, but the relative importance of factors operating in early and later life in influencing risk is unclear, particularly in the case of anxiety.

METHOD

We used data from five cohorts in the Healthy Ageing across the Life Course (HALCyon) collaborative research programme: the Aberdeen Birth Cohort 1936, the Caerphilly Prospective Study, the Hertfordshire Ageing Study, the Hertfordshire Cohort Study and the Lothian Birth Cohort 1921. We used logistic regression to examine the relationship between factors from early and later life and risk of anxiety or depression, defined as scores of 8 or more on the subscales of the Hospital Anxiety and Depression Scale, and meta-analysis to obtain an overall estimate of the effect of each.

RESULTS

Greater neuroticism, poorer cognitive or physical function, greater disability and taking more medications were associated in cross-sectional analyses with an increased overall likelihood of anxiety or depression. Associations between lower social class, either in childhood or currently, history of heart disease, stroke or diabetes and increased risk of anxiety or depression were attenuated and no longer statistically significant after adjustment for potential confounding or mediating variables. There was no association between birth weight and anxiety or depression in later life.

CONCLUSIONS

Anxiety and depression in later life are both strongly linked to personality, cognitive and physical function, disability and state of health, measured concurrently. Possible mechanisms that might underlie these associations are discussed.

Genome-wide association and large-scale follow up identifies 16 new loci influencing lung function

Pulmonary function measures reflect respiratory health and are used in the diagnosis of chronic obstructive pulmonary disease. We tested genome-wide association with forced expiratory volume in 1 second and the ratio of forced expiratory volume in 1 second to forced vital capacity in 48,201 individuals of European ancestry with follow up of the top associations in up to an additional 46,411 individuals. We identified new regions showing association (combined P < 5 × 10(-8)) with pulmonary function in or near MFAP2, TGFB2, HDAC4, RARB, MECOM (also known as EVI1), SPATA9, ARMC2, NCR3, ZKSCAN3, CDC123, C10orf11, LRP1, CCDC38, MMP15, CFDP1 and KCNE2. Identification of these 16 new loci may provide insight into the molecular mechanisms regulating pulmonary function and into molecular targets for future therapy to alleviate reduced lung function.

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk

Blood pressure (BP) is a heritable trait¹ influenced by multiple biological pathways and is responsive to environmental stimuli. Over one billion people worldwide have hypertension (BP ≥140 mm Hg systolic [SBP] or ≥90 mm Hg diastolic [DBP])². Even small increments in BP are associated with increased risk of cardiovascular events³. This genome-wide association study of SBP and DBP, which used a multi-stage design in 200,000 individuals of European descent, identified 16 novel loci: six of these loci contain genes previously known or suspected to regulate BP (GUCY1A3-GUCY1B3; NPR3-C5orf23; ADM; FURIN-FES; GOSR2; GNAS-EDN3); the other 10 provide new clues to BP physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke, and coronary artery disease, but not kidney disease or kidney function. We also observed associations with BP in East Asian, South Asian, and African ancestry individuals. Our findings provide new insights into the genetics and biology of BP, and suggest novel potential therapeutic pathways for cardiovascular disease prevention.

Life course models of socioeconomic position and cardiovascular risk factors: 1946 birth cohort

PURPOSE

To identify the life course model that best describes the association between life course socioeconomic position (SEP) and cardiovascular (CVD) risk factors (ie, body mass index [BMI], systolic and diastolic blood pressure, total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, and glycated hemoglobin) and explore BMI across the life course as mediators of the relationship.

METHODS

The Medical Research Council National Survey of Health and Development was used to compare partial F-tests of simpler nested life course SEP models corresponding to critical period, accumulation, and social mobility models with a saturated model. Then, the chosen life course model for each CVD risk factor was adjusted for BMI at age 53 and lifetime BMI (ages 4, 26, 43, and 53 years).

RESULTS

Among women, SEP was generally associated with CVD risk factors in a cumulative manner, whereas childhood critical period was the prominent model for men. When the best-fitting SEP models were used, we found that adjustment for BMI at age 53 reduced associations for all outcomes in both genders. Further adjustment for lifetime BMI (4, 26, 43, and 53 years) did not substantially alter most associations (except for triglycerides).

CONCLUSIONS

SEP at different points across life influences CVD risk factors differently in men and women.

Comparative analysis of genome-wide association studies signals for lipids, diabetes, and coronary heart disease: Cardiovascular Biomarker Genetics Collaboration

Aims

To evaluate the associations of emergent genome-wide-association study-derived coronary heart disease (CHD)-associated single nucleotide polymorphisms (SNPs) with established and emerging risk factors, and the association of genome-wide-association study-derived lipid-associated SNPs with other risk factors and CHD events.

Methods and results

Using two case–control studies, three cross-sectional, and seven prospective studies with up to 25 000 individuals and 5794 CHD events we evaluated associations of 34 genome-wide-association study-identified SNPs with CHD risk and 16 CHD-associated risk factors or biomarkers. The Ch9p21 SNPs rs1333049 (OR 1.17; 95% confidence limits 1.11–1.24) and rs10757274 (OR 1.17; 1.09–1.26), MIA3 rs17465637 (OR 1.10; 1.04–1.15), Ch2q36 rs2943634 (OR 1.08; 1.03–1.14), APC rs383830 (OR 1.10; 1.02, 1.18), MTHFD1L rs6922269 (OR 1.10; 1.03, 1.16), CXCL12 rs501120 (OR 1.12; 1.04, 1.20), and SMAD3 rs17228212 (OR 1.11; 1.05, 1.17) were all associated with CHD risk, but not with the CHD biomarkers and risk factors measured. Among the 20 blood lipid-related SNPs, LPL rs17411031 was associated with a lower risk of CHD (OR 0.91; 0.84–0.97), an increase in Apolipoprotein AI and HDL-cholesterol, and reduced triglycerides. SORT1 rs599839 was associated with CHD risk (OR 1.20; 1.15–1.26) as well as total- and LDL-cholesterol, and apolipoprotein B. ANGPTL3 rs12042319 was associated with CHD risk (OR 1.11; 1.03, 1.19), total- and LDL-cholesterol, triglycerides, and interleukin-6.

Conclusion

Several SNPs predicting CHD events appear to involve pathways not currently indexed by the established or emerging risk factors; others involved changes in blood lipids including triglycerides or HDL-cholesterol as well as LDL-cholesterol. The overlapping association of SNPs with multiple risk factors and biomarkers supports the existence of shared points of regulation for these phenotypes.

ACTN3 genotype, athletic status, and life course physical capability: meta-analysis of the published literature and findings from nine studies

The ACTN3 R577X (rs1815739) genotype has been associated with athletic status and muscle phenotypes, although not consistently. Our objective was to conduct a meta-analysis of the published literature on athletic status and investigate its associations with physical capability in several new population-based studies. Relevant data were extracted from studies in the literature, comparing genotype frequencies between controls and sprint/power and endurance athletes. For life course physical capability, data were used from two studies of adolescents and seven studies in the Healthy Ageing across the Life Course (HALCyon) collaborative research program, involving individuals aged between 53 and 90+ years. We found evidence from the published literature to support the hypothesis that in Europeans the RR genotype is more common among sprint/power athletes compared with their controls. There is currently no evidence that the X allele is advantageous to endurance athleticism. We found no association between R577X and grip strength (P = 0.09, n = 7,672 in males; P = 0.90, n = 7,839 in females), standing balance, timed get up and go, or chair rises in our studies of physical capability. The ACTN3 R577X genotype is associated with sprint/power athletic status in Europeans, but does not appear to be associated with objective measures of physical capability in the general population. Hum Mutat 32:1–11, 2011. © 2011 Wiley-Liss, Inc.

Absence of association of a single-nucleotide polymorphism in the TERT-CLPTM1L locus with age-related phenotypes in a large multicohort study: the HALCyon programme

Several age-related traits are associated with shorter telomeres, the structures that cap the end of linear chromosomes. A common polymorphism near the telomere maintenance gene TERT has been associated with several cancers, but relationships with other aging traits such as physical capability have not been reported. As part of the Healthy Ageing across the Life Course (HALCyon) collaborative research programme, men and women aged between 44 and 90 years from nine UK cohorts were genotyped for the single-nucleotide polymorphism (SNP) rs401681. We then investigated relationships between the SNP and 30 age-related phenotypes, including cognitive and physical capability, blood lipid levels and lung function, pooling within-study genotypic effects in meta-analyses. No significant associations were found between the SNP and any of the cognitive performance tests (e.g. pooled beta per T allele for word recall z-score = 0.02, 95% CI: -0.01 to 0.04, P-value = 0.12, n = 18,737), physical performance tests (e.g. pooled beta for grip strength = -0.02, 95% CI: -0.045 to 0.006, P-value = 0.14, n = 11,711), blood pressure, lung function or blood test measures. Similarly, no differences in observations were found when considering follow-up measures of cognitive or physical performance after adjusting for its measure at an earlier assessment. The lack of associations between SNP rs401681 and a wide range of age-related phenotypes investigated in this large multicohort study suggests that while this SNP may be associated with cancer, it is not an important contributor to other markers of aging.

Life course trajectories of systolic blood pressure using longitudinal data from eight UK cohorts

BACKGROUND

Much of our understanding of the age-related progression of systolic blood pressure (SBP) comes from cross-sectional data, which do not directly capture within-individual change. We estimated life course trajectories of SBP using longitudinal data from seven population-based cohorts and one predominantly white collar occupational cohort, each from the United Kingdom and with data covering different but overlapping age periods.

METHODS AND FINDINGS

Data are from 30,372 individuals and comprise 102,583 SBP observations spanning from age 7 to 80+y. Multilevel models were fitted to each cohort. Four life course phases were evident in both sexes: a rapid increase in SBP coinciding with peak adolescent growth, a more gentle increase in early adulthood, a midlife acceleration beginning in the fourth decade, and a period of deceleration in late adulthood where increases in SBP slowed and SBP eventually declined. These phases were still present, although at lower levels, after adjusting for increases in body mass index though adulthood. The deceleration and decline in old age was less evident after excluding individuals who had taken antihypertensive medication. Compared to the population-based cohorts, the occupational cohort had a lower mean SBP, a shallower annual increase in midlife, and a later midlife acceleration. The maximum sex difference was found at age 26 (+8.2 mm Hg higher in men, 95% CI: 6.7, 9.8); women then experienced steeper rises and caught up by the seventh decade.

CONCLUSIONS

Our investigation shows a general pattern of SBP progression from childhood in the UK, and suggests possible differences in this pattern during adulthood between a general population and an occupational population. Please see later in the article for the Editors' Summary.

Four-year follow-up of a randomized controlled trial of a social support intervention on infant feeding practices

In a 4-year follow-up of a randomized controlled trial, this study aimed to evaluate the longer-term effects of a peer-led infant feeding intervention that was delivered during the first year of life. The original intervention used monthly home visits from trained volunteers to improve infant feeding practices among a sample of low-income mothers in two disadvantaged London boroughs. Outcome measures at follow-up included children's eating and drinking habits, general and dental health, and BMI. Data were collected via structured face-to-face interviews and postal questionnaires. Of 212 women who completed the original trial, 101 took part in the follow-up (55 intervention, 46 control). Children's mean age at follow-up was 4 years 7 months. There is little evidence that the intervention had an important effect on children's current BMI, caries levels or consumption of fruit and vegetables. However, mothers from the intervention group had better nutritional knowledge and confidence. Intervention group children also consumed more pure fruit juice [relative risk (RR) = 1.57; 95% confidence interval (CI) 0.99, 2.49] and were more likely to never drink squash (RR = 1.76; 95% CI 1.20, 2.58). The data suggest that the original peer support intervention had a small number of positive long-term effects.

Childhood socioeconomic position and objectively measured physical capability levels in adulthood: a systematic review and meta-analysis

BACKGROUND

Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood.

METHODS AND FINDINGS

Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations.

CONCLUSIONS

Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.

Symptoms of depression and anxiety, and change in body mass index from adolescence to adulthood: results from a British birth cohort

BACKGROUND

Depression and anxiety have been shown to be associated with obesity and underweight, but little is known about how the relationship varies across the life course, from adolescence through adulthood. We aimed to investigate the association between adolescent- and adult-onset affective symptoms and body mass index (BMI) change from age 15 to 53 years.

METHOD

We used data from a British birth cohort born in 1946 and followed up ever since. The relationship between affective symptom profiles, distinguishing adolescent-onset and adult-onset symptoms, and BMI change from adolescence to age 53 years was investigated using multilevel models.

RESULTS

Women with adolescent-onset symptoms had lower mean BMI at age 15 years, faster rates of increase across adulthood, and higher BMI at age 53 years than those with no symptoms. Men with adolescent-onset symptoms had lower BMI at all ages from 15 to 53 years. The BMI trajectories of men and women with adult-onset symptoms did not differ from those with absence of symptoms at all ages.

CONCLUSIONS

The relationship between affective symptoms and change in BMI varies by sex and age at onset of symptoms. Adolescence may be an important period for the development of the association between affective symptoms and weight gain in girls. Intervention to prevent increases in BMI across adult life in women with adolescent-onset symptoms, even if they are not overweight at this age, should be considered.

Objective measures of physical capability and subsequent health: a systematic review

Background: measures of physical capability may be predictive of subsequent health, but existing published studies have not been systematically reviewed. We hypothesised that weaker grip strength, slower walking speed and chair rising and shorter standing balance time, in community-dwelling populations, would be associated with higher subsequent risk of fracture, cognitive outcomes, cardiovascular disease, hospitalisation and institutionalisation.

Methods: studies were identified through systematic searches of the electronic databases MEDLINE and EMBASE (to May 2009). Reference lists of eligible papers were also manually searched.

Results: twenty-four papers had examined the associations between at least one physical capability measure and one of the outcomes. As the physical capability measures and outcomes had been assessed and categorised in different ways in different studies, and there were differences in the potential confounding factors taken into account, this made it impossible to pool results. There were more studies examining fractures than other outcomes, and grip strength and walking speed were the most commonly examined capability measures. Most studies found that weaker grip strength and slower walking speed were associated with increased risk of future fractures and cognitive decline, but residual confounding may explain results in some studies. Associations between physical capability levels and the other specified outcomes have not been tested widely.

Conclusions: there is some evidence to suggest that objective measures of physical capability may be predictors of subsequent health in older community-dwelling populations. Most hypothesised associations have not been studied sufficiently to draw definitive conclusions suggesting the need for further research.

Associations between the pubertal timing-related variant in LIN28B and BMI vary across the life course

CONTEXT

The common C allele of rs314276 in LIN28B has been robustly associated with earlier age at menarche in girls and associated with earlier timing of other pubertal traits in both sexes.

OBJECTIVE

Our objective was to explore the associations between rs314276, as a marker of earlier pubertal timing, and body mass index (BMI), weight, and height across the life course.

METHODS

The rs314276 in LIN28B was genotyped in 1242 men and 1209 women born in 1946 and participating in the Medical Research Council National Survey of Health and Development. Birth weight was recorded, and height and weight were measured or self-reported repeatedly at 11 time points between ages 2 and 53 yr. Polynomial mixed models were used to test whether additive genetic associations with sd scores (SDS) for BMI and height changed with age between 0 and 53 yr.

RESULTS

Longitudinal analyses revealed age-dependent associations between rs314276 genotype and BMI (P < 0.001 for genotype-by-age(2) interaction) and body weight (P < 0.001 for genotype-by-age(2) interaction) in women, but not in men. In women only, the C allele at rs314276 was associated with higher BMI SDS from ages 15-43 yr. In contrast, C allele associations with shorter height SDS were apparent in both men and women and did not vary with age.

CONCLUSION

A common genetic variant in LIN28B that confers earlier puberty was associated with a prolonged increase in BMI during adolescence and early to mid-adulthood in women only. Such genetic associations may provide insights into the direct effects of pubertal timing on obesity risk.

Role of lifetime body mass index in the association between age at puberty and adult lipids: findings from men and women in a British birth cohort

Purpose

Why early puberty is associated with worse cardiovascular outcomes is unknown. The relationship between puberty and lipids is unclear. Our aim was to assess whether age at puberty was associated with triglyceride and total low-density lipoprotein and high-density lipoprotein cholesterol at age 53 years.

Methods

Participants in a national birth cohort were examined at 15 years, when pubertal stage for boys was assessed and age at menarche reported by the girls' mothers. At 53 years, 3035 were interviewed in their homes by research nurses, where blood was taken.

Results

There was a significant inverse relationship in women but not men between age at puberty (in years) and triglycerides (regression coefficient −0.2.9, 95% confidence interval −5.5, to −0.04, p = .02), age at puberty, and age at puberty and adult body mass index (BMI; p < .001). Relationships between puberty and lipids were completely explained by BMI or waist circumference at 53 years.

Conclusions

In both sexes earlier maturation was associated with greater BMI and waist circumference in later life, which resulted in greater triglycerides and cholesterol in women. We suggest that intervention after puberty to help avoid obesity in early maturing women may improve their later cardiovascular health.

Childhood social class and adult adiposity and blood-pressure trajectories 36-53 years: gender-specific results from a British birth cohort

BACKGROUND

In this study, the authors investigate gender-specific effects of childhood socio-economic position (SEP) on adiposity and blood pressure at three time points in adulthood.

METHODS

Mixed models were used to assess the association of childhood SEP with body mass index (BMI), waist circumference, systolic blood pressure (SBP) and diastolic blood pressure (DBP) at ages 36, 43 and 53 years in a British birth cohort.

RESULTS

The adverse effect of lower childhood SEP on adiposity increased between ages 36 and 53 years in women (BMI: trend test: p=0.03) and remained stable in men, but the opposite was seen for SBP, where inequalities increased in men (p=0.01). Childhood SEP inequalities in DBP were stable with age in both men and women. Educational attainment mediated some but not all of the effects of childhood SEP on adiposity and SBP, and their rate of change; adult social class was a less important mediator.

CONCLUSION

Childhood SEP is important for adult adiposity and blood pressure across midlife, especially for BMI in women and for blood pressure in men. Thus, pathways to adult health differ for men and women, and public health policies aimed at reducing social inequalities need to start early in life and take account of gender.