Imran Shah

Do childhood cognitive ability or smoking behaviour explain the influence of lifetime socio-economic conditions on premature adult mortality in a British post war birth cohort?

Poor childhood and adult socio-economic conditions, lower childhood cognitive ability and cigarette smoking are all associated with adult mortality risk. Using data on 4458 men and women aged 60 years from a British birth cohort study, we investigated the extent to which these risk factors are part of the same pathway linking childhood experience to adult survival. Compared with women from non-manual origins, men from non-manual origins, women and men from manual origins, and those with missing data on fathers social class had about double the risk of mortality between 26 and 60 years. Cox proportional hazards models showed that these differences were reduced but remained significant after adjusting for childhood cognitive ability, adult socio-economic conditions and smoking. Higher childhood ability increased survival chances by securing better adult socio-economic conditions, such as home ownership, which was strongly associated with survival. These findings were similar for cardiovascular and cancer mortality.

Growth From Birth to Adulthood and Bone Phenotype in Early Old Age: A British Birth Cohort Study

There is growing evidence that early growth influences bone mass in later life but most studies are limited to birth weight and/or early infant growth and dual‐energy X‐ray absorptiometry (DXA) measurements. In a British birth cohort study with prospective measures of lifetime height and weight, we investigated the growth trajectory in relation to bone in males (M) and females (F) at 60 to 64 years old. Outcomes were DXA measures of hip and spine areal bone density (aBMD) (n = 1658) and pQCT measures of distal and diaphyseal radius cross‐sectional area (CSA), strength, and volumetric bone density (vBMD) (n = 1350 of the 1658). Regression models examined percentage change in bone parameters with standardized measures of birth weight, height, and weight. A series of conditional growth models were fitted for height and weight gain (using intervals: birth–2, 2–4, 4–7, 7–15, 15–20, 20–36, and 36–64 years) and height gain (using intervals: 2–4, 4–7, 7–15, and 15–36 years). Birth weight was positively related to bone CSA (M: 1.4%; 95% confidence interval [CI], 0.3%–2.5%; F: 1.3%; 95% CI, 0.3%–2.4% per 1 SD increase in birth weight for diaphyseal CSA) and strength (M: 1.8%; 95% CI, 0.3–3.4; F: 2.0%; 95% CI, 0.5–3.5). No positive associations were found with trabecular, total, or cortical vBMD. One SD change in prepubertal and postpubertal height and weight velocities were associated with between 2% and 5% greater bone CSA and strength. Height gain in later years was negatively associated with trabecular vBMD. Weight gain velocity during the adult years was positively associated with up to 4% greater trabecular and total BMD, and 4% greater aBMD at hip and spine. In a cohort born in the early post‐war period, higher birth weight, gaining weight and height faster than others, particularly through the prepubertal and postpubertal periods, was positively related to bone strength, mostly through greater bone CSA, at 60 to 64 years.

Is chair rise performance a useful measure of leg power

Background and aims: Chair rise performance, which is simple to assess in a home or clinic setting, has been used as a method of predicting leg power deficit in older adults. More recently, chair rise performance has been assessed in younger populations as a baseline for assessment of subsequent age-related declines in function and power. However, as rising from a chair repeatedly not only requires lower limb strength and power but also good balance and coordination, it may not be purely a measure of leg power especially among these younger, well functioning groups who are yet to experience agerelated declines and deficits in function. The aim of this study was to assess whether chair rise performance can be considered as a predictor of leg power, and hence of deficits in this, in men and women in mid-life. We assessed the relationship of chair rise performance with leg extensor power (LEP), measured using the Nottingham Power Rig (NPR), and with standing balance performance. Methods: LEP was measured in a clinic setting in a sub-sample of 81 men and 93 women from the MRC National Survey of Health and Development, a nationally representative cohort born in Britain in 1946. The time taken to rise from a chair 10 times and standing balance time were assessed during home visits at the same age. Results: Increasing LEP was associated with better chair rise performance among those who completed 10 chair rises in ≥15 seconds, after adjustment for body size (p=0.008). Better standing balance performance was associated with better chair rise performance in men, but not women. Conclusions: That LEP and standing balance are both related to chair rise time in men suggests that chair rise time should not be thought of purely as a proxy measure of leg power in middle-aged populations. This has implications for longitudinal studies which want to study age-related decline in chair rise performance.

Childhood, adolescent and early adult body mass index in relation to adult mortality: results from the British 1946 birth cohort

Background Adult body mass index (BMI) has been consistently related to mortality, but little is known about the impact of earlier life BMI on adult mortality. The aim is to investigate the impact of childhood, adolescent and early adult BMI on premature adult all-cause mortality. Methods The British 1946 cohort study was used to assess the association of BMI in childhood, adolescence and adulthood with mortality 26–60 years (332 deaths). 4462 (83%) respondents were available for analysis at age 26 years. Splines were used in Cox regression to model the associations between BMI and mortality. Results In both genders, adult BMI from 20 years onwards showed a consistent U-shaped relationship with adult mortality (overall p value <0.05 for BMI at ages 20, 26 and 36 years). In women, a similar relationship was observed for adolescent BMI at 15 years (p=0.02); the HR comparing women with low BMI (2 SDs below mean) versus mean BMI was 2.96 (95% CI 1.26 to 6.97). The corresponding HR for women with BMI 2 SDs above the mean was 1.97 (0.95 to 4.10). BMI in childhood was generally not associated with adult mortality except female BMI at 4 years where a U-shaped relationship was observed (p=0.02); HR for BMI 2 SDs below mean versus mean was 2.13 (0.97 to 4.70) and the corresponding HR for 2 SDs above the mean was 1.67 (0.85 to 3.28). This association was not attenuated by subsequent BMI change or mediators. Conclusions High and low BMI from early adulthood were related to adult premature mortality suggesting that promoting a normal weight in early adulthood could prevent premature mortality.

Psychiatric disorder in early adulthood and risk of premature mortality in the 1946 British Birth Cohort

BackgroundFew studies of the association between psychiatric disorder and premature death have adjusted for key confounders and used structured psychiatric interviews. We aimed to investigate if psychiatric disorder was associated with a higher risk of mortality and whether any excess mortality was due to suicide, or explained by other health or socioeconomic risk factors.MethodsWe used data from the MRC National Survey of Health and Development, a nationally representative UK birth cohort. 3283 men and women completed the Present State Examination at age 36. The main outcome measure was all-cause mortality before age 60.ResultsThose with psychiatric disorder at age 36 had a higher risk of death even after adjusting for potential confounders (Hazard ratio = 1.84, 95% C.I. 1.22-2.78). Censoring violent deaths and suicides led to similar results.ConclusionsPsychiatric disorder was associated with excess premature mortality not explained by suicide or other health or socioeconomic risk factors.

Association between resting heart rate across the life course and all-cause mortality: longitudinal findings from the Medical Research Council (MRC) National Survey of Health and Development (NSHD)

Background Resting heart rate (RHR) is an independent risk factor for mortality. Nevertheless, it is unclear whether elevations in childhood and mid-adulthood RHR, including changes over time, are associated with mortality later in life. We sought to evaluate the association between RHR across the life course, along with its changes and all-cause mortality. Methods We studied 4638 men and women from the Medical Research Council (MRC) National Survey of Health and Development (NSHD) cohort born during 1 week in 1946. RHR was obtained during childhood at ages 6, 7 and 11, and in mid-adulthood at ages 36 and 43. Using multivariable Cox regression, we calculated the HR for incident mortality according to RHR measured at each time point, along with changes in mid-adulthood RHR. Results At age 11, those in the top fifth of the RHR distribution (≥97 bpm) had an increased adjusted hazard of 1.42 (95% CI 1.04 to 1.93) for all-cause mortality. A higher adjusted risk (HR, 95% CI 2.17, 1.40 to 3.36) of death was also observed for those in the highest fifth (≥81 bpm) at age 43. For a >25 bpm increased change in the RHR over the course of 7 years (age 36–43), the adjusted hazard was elevated more than threefold (HR, 95% CI 3.26, 1.54 to 6.90). After adjustment, RHR at ages 6, 7 and 36 were not associated with all-cause mortality. Conclusions Elevated RHR during childhood and midlife, along with greater changes in mid-adulthood RHR, are associated with an increased risk of all-cause mortality.

Childhood Stunting and Mortality Between 36 and 64 Years: The British 1946 Birth Cohort Study

Background: Our aim was to examine the associations between childhood or adult height and adult mortality. Methods: In the prospective British 1946 Birth Cohort Study, childhood height was measured at 2, 4, 6, 7, 11, and 15 years, and adult height was measured at 36 years. Deaths were reported from the national health service register. Results: A total of 3877 study members (1963 male) contributed 106,333 person-years of follow-up; 391 deaths (228 male) were reported between the ages of 36 and 64 years. The strongest sex-adjusted association between height and mortality between ages 36 and 64 years was seen for height at age 6 years. The association was nonlinear; only study members in the shortest quintile at 6 years had a higher relative risk of adult mortality compared with those in the tallest quintile. By contemporary growth standards, 5.7% (n = 188) had heights at 6 years less than the second percentile, and a further 15.0% (n = 490) had heights between the second to ninth percentiles; these groups had higher adult mortality than all other study members (hazard ratio, 2.18; 95% confidence interval, 1.52–3.13; P < .001; and hazard ratio, 1.42; 95% confidence interval, 1.08–1.88; P = .01, respectively). Several determinants of childhood stunting (height at 6 years less than the second percentile) were directly associated with adult mortality; these included shorter parental heights and adverse early life nutrition and housing. Conclusions: British men and women born in 1946 were relatively stunted as children by contemporary standards. Those who were short at age 6 years had substantially higher mortality 30 to 60 years later. Furthermore, they accounted for the well-recognized inverse association between adult height and mortality.

MUC5AC and inflammatory mediators associated with respiratory outcomes in the British 1946 birth cohort.

Dysregulation of respiratory mucins, MUC5AC in particular, has been implicated in respiratory disease and MUC5AC expression is up‐regulated in response to environmental challenges and inflammatory mediators. The aim of this study was to examine the effect of genetic variation on susceptibility to common respiratory conditions.

Enabling access to british birth cohort studies: A Secure Web Interface for the NSHD (SWIFT)

This paper provides an overview of the new Secure Web Interface for the Medical Research Council (MRC) National Survey of Health and Development (NSHD), which is a web-based data and metadata access system for the longest-running longitudinal study of health in the world [1]. Accessing NSHD metadata and data has often been a challenge for external (non-MRC) users, because the underlying data and metadata formats have changed dramatically in 63 years of operation, and because the processes involved in metadata search and data access were manual and usually required “on-site” access [2]. The design goals of the SWIFT include maintaining confidentiality and privacy of study members, enabling metadata search access to internal (MRC) and external users, facilitating data downloading and extraction from a range of underlying formats, and implementing procedures to ensure compliance with the governance policies of the MRC and the NSHDs governance panel. This paper details some of the challenges and successes of the MRC pathfinder “Data Access Project” to enable access using SWIFT while protecting the study members and their data.

Publisher Correction: Associations of statin use with motor performance and myalgia may be modified by 25-hydroxyvitamin D: findings from a British birth cohort

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