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Biomedical subjects

A Aihie Sayer

Publications and source records attributed to A Aihie Sayer.

16 recordsLinked to original sources
PubMed2006

Parental determinants of neonatal body composition.

BACKGROUND: The prevalence of both childhood and adult obesity is rising in the developed world, and there is increasing interest in its underlying causes. A number of studies suggest a positive relationship between birth weight and childhood body mass index, but less is known about specific prenatal environmental influences on more direct measures of obesity. We used data from the Southampton Women's Survey to investigate parental influences on neonatal body composition ascertained by dual x-ray absorptiometry. METHODS: Participating mothers were characterized in detail (anthropometry, lifestyle, diet) before and during pregnancy; information was also obtained on their partners. The offspring underwent assessment of fat and lean body mass by dual x-ray absorptiometry within 2 wk of birth. Linear regression methods were used to explore the parental determinants of neonatal body composition. RESULTS: Complete data were available for 448 mother-offspring pairs. Taller women and those with higher parity had offspring with increased birth weight, fat, and lean mass (P < 0.05). Mothers who were taller, of greater parity, had greater fat stores, or walked more slowly also had offspring with greater proportionate body fat at birth (all P < 0.05). There was a weaker trend toward lower percentage fat and greater percentage lean in the offspring of mothers who smoked during pregnancy. CONCLUSION: Maternal size, parity, smoking history, walking speed, and fat stores are independent determinants of neonatal body composition. If these influences are shown to have persisting effects on body composition through to adulthood, they point to novel public health interventions early in life to prevent later obesity.

Adipose Tissue↗
PubMed2006

Relationships between SF-36 health profile and bone mineral density: the Hertfordshire Cohort Study.

We utilised the Hertfordshire Cohort Study (HCS) to relate bone mineral density (BMD) to SF-36 health-related quality of life scores. We studied 737 men and 675 women who had completed a home interview and clinic. Four hundred and ninety-eight men and 468 women subsequently attended for bone densitometry [dual-energy X-ray absorptiometry (DXA)]. SF-36 questionnaire responses were mapped to eight domains: physical function (PF), role physical (RP), role emotional (RE), social functioning (SF), mental health (MH), vitality (VT), bodily pain (BP) and general health perception (GH). Subjects with scores in the lowest gender-specific fifth of the distribution were classified as having "poor" status for each domain. Odds ratios (OR) for poor status for each domain were calculated per unit increase in lumbar spine or total femoral BMD t score. Among men after adjustment for age, BMI, social class, lifestyle (including physical activity) and known comorbidity, higher total femoral t score was associated with decreased prevalence of poor SF-36 scores for PF [OR 0.72 (95%CI 0.53, 0.97), p=0.03], SF [OR 0.70 (95%CI 0.53, 0.94), p=0.02] or GH domains [OR 0.74 (95%CI 0.56, 0.99), p=0.05], but no relationships were apparent between SF-36 scores and lumbar spine t score. Among women, the adjusted relationship between higher total femoral t score and decreased prevalence of poor PF was consistent [OR 0.71 (95%CI 0.50, 1.00), p=0.05], but no other relationships were significant. Poorer functioning (assessed by SF-36 questionnaire) is associated with lower total femoral BMD in older men (but less so in women) after adjustment for lifestyle factors and comorbidity.

Aged↗
PubMed2006

Is hand-held dynamometry useful for the measurement of quadriceps strength in older people? A comparison with the gold standard Bodex dynamometry.

BACKGROUND: The lower limb muscle strength is an important determinant of physical function in older people. However, measurement in clinical and epidemiological settings has been limited because of the requirement for large-scale equipment. A protocol using a novel, versatile hand-held dynamometer (HHD) has been developed to measure the quadriceps strength in a supine position. OBJECTIVE: The objective of this study was to assess the validity of this new methodology for measuring the lower limb muscle strength compared to the gold standard Biodex dynamometer. METHODS: The supine quadriceps strength was measured twice with each of the Biodex and the HHD in 20 men and women, aged 61-81 years, on their non-dominant leg. The agreement between the peak torques obtained by Biodex and HHD was analyzed. RESULTS: The mean peak Biodex and HHD results were 83.4 +/- (SD) 28.0 Nm and 68.9 +/- 19.6 Nm, respectively. The HHD undermeasured the quadriceps strength by an average of 14.5 Nm (95% CI 8.5, 20.6) compared to the Biodex, and this effect was most marked in the strongest participants. Nevertheless, there was a good correlation between the measures (r = 0.91, p < 0.0001). Classification of individuals into tertiles of muscle strength showed good agreement between the two methods (Kappa = 0.69, p < 0.0001). CONCLUSIONS: Our findings suggest that the HHD using a supine positioning offers a feasible, inexpensive, and portable test of quadriceps muscle strength for use in healthy older people. It underestimates the absolute quadriceps strength compared to the Biodex particularly in stronger people, but is a useful tool for ranking muscle strength of older people in epidemiological studies. It may also be of value for quick and objective assessment of physical function in the clinical setting.

Age Factors↗
PubMed2005

Birth weight, infant weight gain, and cause-specific mortality: the Hertfordshire Cohort Study.

Low birth weight, a marker of adverse intrauterine circumstances, is known to be associated with a range of disease outcomes in later life, including coronary heart disease, hypertension, type 2 diabetes, and osteoporosis. However, it may also decrease the risk of other common conditions, most notably neoplastic disease. The authors describe the associations between birth weight, infant weight gain, and a range of mortality outcomes in the Hertfordshire Cohort. This study included 37,615 men and women born in Hertfordshire, United Kingdom, in 1911-1939; 7,916 had died by the end of 1999. For men, lower birth weight was associated with increased risk of mortality from circulatory disease (hazard ratio per standard deviation decrease in birth weight = 1.08, 95% confidence interval: 1.04, 1.11) and from accidental falls but with decreased risk of mortality from cancer (hazard ratio per standard deviation decrease in birth weight = 0.94, 95% confidence interval: 0.90, 0.98). For women, lower birth weight was associated with a significantly (p < 0.05) increased risk of mortality from circulatory and musculoskeletal disease, pneumonia, injury, and diabetes. Overall, a one-standard-deviation increase in birth weight reduced all-cause mortality risk by age 75 years by 0.86% for both men and women.

Adult↗
PubMed2005

Birth weight and weight at 1 year are independent determinants of bone mass in the seventh decade: the Hertfordshire cohort study.

Several studies have shown relationships between growth in early life and adult bone mass; in this article, we evaluate the relative contributions of pre- and postnatal factors to bone mass in the seventh decade. A total of 498 eight men and 468 women who were born in Hertfordshire during the period 1931-1939 and still living there were recruited. Detailed birth records were available. Participants attended a clinic where they completed a detailed health questionnaire, before performance of anthropometric measurements and bone densitometry of the proximal femur and lumbar spine (Hologic QDR 4500). Birth weight was associated with bone mineral content in both men (proximal femur: r=0.16, p=0.0003; lumbar spine: r=0.10, p=0.03) and women (proximal femur: r=0.16, p=0.0008; lumbar spine: r=0.11, p=0.03); relationships with bone mineral density were weaker and were significant at the proximal femur in men only (p=0.03). Relationships between weight at 1 y and bone mineral content were even stronger (proximal femur: men r=0.22, p<0.0001; women r=0.14, p=0.002). In men, 18% of the variance in proximal femoral bone area was explained by a model that included birth weight, weight at 1 y, and adult weight, with the relative contributions attributed to each being 2.8, 6.8, and 8.2%, respectively. In women, similar modeling produced figures of 6.7, 4.2, and 3.9% (overall variance of 15% in proximal femoral bone area). Hence, weight at each of these three points in the life course is important in the determination of adult bone mass, with greater contributions of earlier growth to bone size and mineral content than to bone mineral density.

Adult↗
PubMed2004

Type 2 diabetes mellitus is associated with increased axial bone density in men and women from the Hertfordshire Cohort Study: evidence for an indirect effect of insulin resistance?

AIMS/HYPOTHESIS: Previous studies have suggested that the high bone density often observed in type 2 diabetic patients may be explained by insulin resistance. We explored this hypothesis in the Hertfordshire Cohort Study. METHODS: A total of 465 men and 444 women aged 59 to 71 years and with no prior diagnosis of diabetes attended a clinic where a glucose tolerance test was performed and bone density measured at the femoral neck and lumbar spine. Biochemical markers of bone turnover (serum osteocalcin and urinary mean c-terminal cross-linking telopeptide of type II collagen) were measured in 163 men. RESULTS: According to WHO criteria, 83 men and 134 women were diagnosed with impaired glucose tolerance and a further 33 men and 32 women were diagnosed as having type 2 diabetes. Bone density was higher in newly diagnosed diabetic subjects, with relationships stronger in women (p<0.001) than men (p<0.05) and attenuated by adjustment for body mass index. In both sexes, we observed positive correlations between the total femur and femoral neck bone mineral density with measures of insulin resistance (r=0.17-0.22), with stronger results observed in women. These relationships did not apply after adjustment for body mass index. Glucose status did not lead to differences in osteocalcin level or c-terminal cross-linking telopeptide of type II collagen levels. CONCLUSIONS/INTERPRETATION: Our findings suggest that hyperinsulinaemia may affect bone mineral density through indirect effects, e.g. body weight.

Aged↗
PubMed2003

Weight from birth to 53 years: a longitudinal study of the influence on clinical hand osteoarthritis.

OBJECTIVE: To determine the influence of body weight throughout the life course on the development of clinical hand osteoarthritis (OA). METHODS: A British national survey was used to perform a prospective cohort study of 1,467 men and 1,519 women born in 1946. Weight was measured at birth and at subsequent followup visits through childhood and adulthood. The main outcome measure was the odds ratio for the presence of hand OA at the age of 53 years. RESULTS: Two hundred eighty men (19%) and 458 women (30%) had OA in at least 1 hand joint. Hand OA was significantly associated with increased weight at ages 26 years, 43 years, and 53 years and with decreased weight at birth in men. Birth weight and adult weight showed independent effects, such that men with the highest risk for OA represented those who had been heaviest at age 53 years and lightest at birth. These findings were not explained by grip strength. There was no significant relationship between weight and hand OA in women. CONCLUSION: The results of this study show that increased adult weight is associated with, and may precede, development of hand OA in men. An association between hand OA and weight was not observed in women. The relationship between hand OA and decreased birth weight is a new finding and may reflect the persisting influence of prenatal environmental factors on adult joint structure and function.

Adolescent↗
PubMed2002

Early diet and growth: impact on ageing.

The modification of ageing by nutritional intervention is well recognised. Post-weaning diet restriction is the only widely reproducible method to slow ageing, but the effects of prenatal and preweaning diet restriction have been less well characterised. There is some evidence that diet restriction instituted in utero or shortly after birth may have an opposite effect and be associated with increased ageing, and recent work suggests that it may shorten lifespan. Interest in this area has been rekindled by the growing body of epidemiological evidence showing that a number of age-related diseases are associated with poor growth and inadequate nutrition in early life. The relevance of this association to structural and functional ageing changes in different systems is now being considered. Work on musculo-skeletal ageing has demonstrated that loss of muscle strength and bone mass is greater in individuals who did not grow well in early life, and a range of studies suggests that maternal, developmental and nutritional factors are important. The underlying mechanisms remain speculative, and it remains to be determined whether they are system-specific or universal throughout the body. A new cohort of subjects aged between 60 and 70 years is being established to investigate how genetic factors interact with growth and nutritional influences to programme musculo-skeletal ageing in later life.

Aging↗
PubMed1999

Do all systems age together?

BACKGROUND: Aging changes in different body system are well described, but few studies have considered the relationship between them. OBJECTIVE: The purpose of this study was, therefore, to investigate the interrelationships between markers of aging in different parts of the body. METHODS: A cross-sectional study design was used. Structural and functional markers of aging were measured in a number of different body systems. RESULTS: Conditional independence analysis demonstrated that the aging markers selected clustered into two groups, either related to chronological age or adult height. Visual acuity, lens opacity, hearing threshold, cognitive decline, and the number of teeth were associated with age, while systolic blood pressure and skin thickness were related to height. Grip strength was associated with both. CONCLUSIONS: The differential associations of the aging markers with chronological age and adult height suggest that different systems do not age together. This may have relevance for understanding what underlies aging, and these preliminary findings now require replication in other aging cohorts.

Aged↗
PubMed1998

Does raised intraocular pressure begin in utero?

AIM: To determine whether fetal and infant growth, as assessed by weight at birth and weight at 1 year, are related to intraocular pressure. METHODS: 717 men and women born in Hertfordshire between 1920 and 1930, for whom records of birth weight and weight at 1 year were available, were examined. Visual fields were assessed using the Takagi central 25 degrees 75 point static threshold screening program. Tonometry was performed using the Perkin's tonometer. The disc was assessed by direct ophthalmoscopy through dilated pupils. RESULTS: A significant inverse relation was found between systolic blood pressure and birth weight. However, no association was found between birth weight or weight at 1 year and intraocular pressure, cup/disc ratio, or visual field defects. CONCLUSIONS: There was no evidence to support fetal or infant growth as being important factors for the subsequent development of raised intraocular pressure.

Aged↗
PubMed1998

Age-related nuclear lens opacities are associated with reduced growth before 1 year of age.

PURPOSE: The aim of this study was to assess the relationship between fetal and infant growth, as measured by birthweight and weight at 1 year and the development of age-related lens opacities. METHODS: A total of 1428 men and women who were born in Hertfordshire, United Kingdom, between 1920 and 1930, and for whom records of birthweight and weight at 1 year were available, were traced and invited for examination. Of these, 717 (50%) attended for ophthalmic examination. After dilation with tropicamide 1%, lens opacities were graded using the Lens Opacities Classification System (LOCS) III. RESULTS: In this population of English men and women aged 64 to 74 years, most opacities were of the nuclear type. There was no association between birthweight and nuclear lens opacities. Weight at 1 year was negatively correlated with nuclear opacity score in adult life (P=0.001). Subjects in the highest tertile for weight at 1 year (>23 pounds) had an odds ratio of 0.35 (95% confidence interval, 0.17 to 0.74) for having a significant nuclear lens opacity (LOCS score of > or = 3) compared with people in the lowest tertile for weight at 1 year (<21 pounds). This association remained after controlling for age, sex, smoking, social class, adult height, and diabetes. CONCLUSIONS: To our knowledge, this is the first time that such an association has been reported; it needs to be replicated in other populations. It could provide part of the explanation for the observed excess risk of cataract in developing countries.

Aged↗
PubMed1997

Undernutrition and aging.

Diet restriction is a well-recognised method of slowing aging and prolonging life span in animals. However, previous studies of this have tended to start after weaning and the effects of prenatal or early postnatal diet restriction have rarely been considered. Here we summarise the existing literature, which suggests that reducing nutrition at this earlier stage of life has opposite effects, resulting in accelerated aging and a reduction in life span. These findings support emerging epidemiological evidence in man that poor nutrition in early life may programme accelerated aging and predispose to a variety of age-related diseases.

Aging↗
PubMedDate not supplied

Prenatal exposure to a maternal low protein diet shortens life span in rats.

BACKGROUND: Postweaning diet restriction is associated with prolongation of life span, reduced age-related disease and slower ageing. The effects of diet restriction imposed prior to weaning have not been so well characterised, but studies suggest an opposite effect with increased age-related diseases occurring in offspring exposed to undernutrition in prenatal life. It remains unclear whether life span is similarly adversely affected by early diet restriction. OBJECTIVE: The present study in rats aimed to evaluate the impact of a maternal low protein diet upon the life span of the resulting offspring. METHODS: Rat dams were fed either a 180-gram casein/kg control diet or a 90-gram casein/kg low protein diet from conception until the end of pregnancy. The offspring were then maintained with minimal handling until death from natural causes or distress-necessitated euthanasia. RESULTS: The average life span of female rats exposed to low protein diets in utero was reduced by 11% (p = 0.044, Kaplan-Meier analysis). There was a similar but non- significant trend in the male offspring (control 76 +/- 3 weeks, low protein 73 +/- 3 weeks). In addition the rats exposed to a prenatal low protein diet had significantly higher systolic blood pressure at 4 weeks of age and tended to be smaller than control animals in postnatal life. CONCLUSION: The results suggest that intrauterine diet restriction reduces life span in rats and contrasts with the well-recognised increase in life span produced by postweaning diet restriction. The timing of the nutritional intervention appears to be critical and recognition of this is relevant to understanding the mechanisms underlying the effects of diet restriction on ageing and life span.

Animal Nutritional Physiological Phenomena↗