Biomedical subjects

Marcus Richards

Publications and source records attributed to Marcus Richards.

21 records · Page 2Linked to original sources

PubMed2002

Birthweight, postnatal growth and cognitive function in a national UK birth cohort.

BACKGROUND: Birthweight is associated with cognition and educational attainment across the full birthweight range in the normal population, independently of social background. However, the extent to which birthweight reflects fetal growth, or is a marker of subsequent size, with respect to this association, is not clear. We therefore investigated the independent effects of birthweight and postnatal height adjusted for postnatal weight on cognitive function and educational attainment while controlling for family background. METHODS: Using the British 1946 birth cohort we investigated the association between cognitive function at various ages and birthweight, height adjusted for weight in childhood and adulthood, and educational attainment, controlling for sex, father's social class, maternal education, birth order, and maternal age. RESULTS: Birthweight was positively associated with cognition up to age 26, and with the likelihood of obtaining advanced educational qualifications. Height was positively associated with cognition at all ages, and also with educational attainment. Weight was not associated with cognition at ages 8 and 15, but was negatively associated with verbal ability at age 26, with verbal memory at age 43, and with educational attainment. These effects were independent of each other, and of family background. Conditional analyses suggested the positive effect of height growth on cognition at two intervals, one in early childhood, and the other in late adolescence. In addition, weight gain after age 15 was negatively associated with cognition at 26. CONCLUSION: Birthweight and postnatal growth are independently associated with cognition.

Adult↗

PubMedDate not supplied

Cognitive function across the life course and the menopausal transition in a British birth cohort.

OBJECTIVE: Despite biological plausibility, relationships between menopause and cognitive function are inconsistent. We investigated whether menopause status and menopause age were associated with general cognitive ability, verbal memory, and visual search speed and concentration in a large cohort of women while considering vasomotor and psychological symptoms, previous childhood and adult measures of cognitive function, lifetime socioeconomic circumstances, educational attainment, lifestyle factors, and chronic diseases. DESIGN: A nationally representative British cohort of 1261 women born in March 1946 and all aged 53 years at cognitive testing, with prospective information on previous cognitive function, menopausal characteristics, and potential confounders. RESULTS: There was only weak evidence of the effect of natural menopause on cognitive function and no evidence of any effects of hormone therapy use or hysterectomy status. There was a trend across the phases of the natural menopausal transition (pre-, peri-, and postmenopause) for the National Adult Reading Test (P = 0.005) and search speed and concentration (P = 0.042), with postmenopausal women having the lowest cognitive function, but there was no trend in verbal memory. Variation in vasomotor and psychological symptoms did not explain these trends. In postmenopausal women, there was a positive trend across menopause age for verbal memory (P = 0.004) and a weak positive trend for the National Adult Reading Test (P = 0.052), with women who reached menopause later having higher cognitive function. Previous cognitive function generally explained the associations, which were further weakened by adjusting for socioeconomic and educational confounders. One exception was the association between the natural menopause transition and search speed and concentration, which remained after adjustment for these factors. CONCLUSION: Menopause adversely affects cognitive function, but this effect may be largely explained by premenopausal cognitive function. These findings suggest that common environmental or genetic factors, operating through long-term or lifelong hormonal mechanisms, may influence the timing of natural menopause and lifetime cognitive function.

Age Factors↗

PubMedDate not supplied

Lung function and cognitive ability in a longitudinal birth cohort study.

OBJECTIVE: The objective of this study was to examine the association between forced expiratory volume in 1 second (FEV1) and cognitive ability in midlife in the normal population. METHODS: Multiple regression was used to test associations between FEV1 and cognitive function in 1778 men and women in the MRC National Survey of Health and Development, also known as the British 1946 birth cohort. Analyses were adjusted for sex, body size (birth weight, adult height, weight, and chest circumference), socioeconomic status, lifetime smoking, and a range of health indicators, including early respiratory vulnerability (infant lower respiratory infection, childhood asthma, and exposure to atmospheric pollution). RESULTS: FEV1 at 43 years was associated with slower psychomotor speed (peg placement) at the same age and with slower decline in psychomotor speed (letter search speed) from 43 to 53 years, independently of the previously mentioned potential confounders. These independent associations were not observed, however, for adult verbal ability, verbal memory, or rate of decline in memory, which were significantly explained by socioeconomic status and adolescent cognitive ability. In a subsequent analysis, adolescent cognition was positively associated with FEV1, although not with rate of decline in FEV1 from 43 to 53 years, again independently of the previously mentioned confounders. CONCLUSIONS: Cognitive function and FEV1 are positively associated across the life course. One possible explanation lies in the parallel action of endocrine, autonomic, and motor control systems on respiration and higher mental function. Because respiration and mental function are both associated with functional capacity and survival, this is a matter of potential clinical significance.

Adolescent↗