Adiponectin and Leptin Trajectories in Mexican-American Children from Birth to 9 Years of Age

Objectives

To address molecular mechanisms underlying obesity development, we examined patterns of critical metabolism-related hormones, adiponectin and leptin (adipokines), over childhood.

Subjects and Design

Plasma adiponectin and leptin were measured in 80 Mexican-American children at birth and again at 2, 5, and 9 years from the ongoing prospective cohort followed by the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS). We used a mixture modeling approach to identify patterns in adipokine trajectories from birth to 9 years.

Results

Leptin was positively related to child body size within all ages, however adiponectin had inverse and weaker associations with BMI at 2, 5, and 9 years. Correlations between adipokine levels over the 0–2, 2–5, and 5–9-year periods increased for both leptin (r = 0.06, 0.31 and 0.62) and adiponectin (r = 0.25, 0.41 and 0.46). Our mixture modeling approach identified three trajectory clusters for both leptin (1L [slowly-rising], 2L [rapidly-rising], and 3L [stable]) and adiponectin (1A [steep-dropping and rebounding], 2A [moderately-dropping], and 3A [stable]). While leptin groups were most separated over the 2–9-year period, adiponectin trajectories displayed greatest heterogeneity from birth to 2 years. Children in the rapidly-rising 2L group had highest BMI and waist circumference at 9 years. Further, children with greater birth weight had increased odds of belonging to this high risk group (OR = 1.21 95% CI 1.03, 1.43, compared to stable group 3L). Children whose mothers consumed more sugar-sweetened beverages during pregnancy were at risk of being in the steep-dropping 1A group (OR = 1.08, 95% CI 1.01, 1.17, compared to stable group 3A).

Conclusion

Our results highlight developmental differences in leptin and adiponectin over the childhood period. Leptin closely reflects child body size however factors affecting adiponectin and long-term consequences of its changes over infancy need to be further explored.     

Childhood Maltreatment and BMI Trajectories to Mid-Adult Life: Follow-Up to Age 50y in a British Birth Cohort

Background

Childhood maltreatment including abuse and neglect has been associated with adult obesity, but evidence on life-course development of obesity or BMI gain is unclear. We aim to establish whether childhood maltreatments are related to obesity or BMI at different life-stages 7y-50y and to identify possible explanations for associations.

Methods

Childhood physical, psychological and sexual abuse, neglect and BMI at seven ages were recorded in the 1958 birth cohort (n~15,000). Associations of child maltreatments with BMI at separate ages were tested using linear regression or logistic regression for obesity, and with rate of child-to-adult BMI gain using multilevel models. We adjusted for potential covariates.

Results

Abuse was reported in ~12% of the population. Abuse was not associated with elevated childhood BMI, but adult associations were observed: i.e. the abused had faster child-adult BMI gain than the non-abused; associations were independent of adult covariates. For physical abuse in both genders there was a positive linear association of ~0.006/y zBMI gain with age after adjustment for all covariates. Similarly, there was a linear association of physical abuse with obesity risk: e.g. among females from a low OR_adjusted of 0.34 (0.16,0.71) at 7y to 1.67 (1.25,2.24) at 50y. In females faster zBMI gains with age of ~0.0034/y were observed for sexual abuse and increases in obesity risk were faster: from a low OR_adjusted of 0.23 (0.06,0.84) at 7y to 1.34 (0.86,2.10) at 50y. Psychological abuse and neglect associations were less consistent.

Conclusions

Childhood maltreatment associations with BMI or obesity varied across life: physical and, in females, sexual abuse were associated with faster lifetime BMI gains, which may have detrimental long-term health consequences.     

Stunting at 2 Years in Relation to Body Composition at 9 Years in African Urban Children**

Objective: To determine whether African urban children who were stunted at 2 years of age demonstrated an altered body composition by the end of childhood, before entering puberty, at 9 years of age. Research Methods and Procedures: This was a mixed‐longitudinal study of 330 prepubertal African children (182 boys) from Soweto‐Johannesburg, South Africa. Anthropometric data at 2 years of age were compared with anthropometric, DXA‐determined body composition and fat patterning in late childhood (7 to 9 years). Results: Children who had been stunted at 2 years were significantly shorter and lighter than non‐stunted children at 7 to 9 years, but there were no differences in their BMI or centralization of body fat. Previously stunted status significantly predicted reduced weight and height at 7 to 9 years but did not predict BMI, body composition, or fat patterning after controlling for potential confounding factors. The odds ratio for stunting at 2 years as a predictor of overweight at 7 to 9 years was not significant at 1.09 (95% confidence limits: 0.30, 3.98). Discussion: Greater BMI in stunted infants does not demonstrate a tendency toward overweight or obesity but is a reflection of the greater reduction in height rather than weight in stunted children. Stunted children may be programmed to accumulate greater body fat at central sites during adolescence, but we have been unable to show that these changes are evident before the initiation of pubertal development.     

Validation of Self-Reported Information on Dental Caries in a Birth Cohort at 18 Years of Age

Objective

Estimate the prevalence of dental caries based on clinical examinations and self-reports and compare differences in the prevalence and effect measures between the two methods among 18-year-olds belonging to a 1993 birth cohort in the city of Pelotas, Brazil.

Method

Data on self-reported caries, socio-demographic aspects and oral health behaviour were collected using a questionnaire administered to adolescents aged 18 years (n = 4041). Clinical caries was evaluated (n = 1014) by a dentist who had undergone training and calibration exercises. Prevalence rates of clinical and self-reported caries, sensitivity, specificity, positive and negative predictive values, absolute and relative bias, and inflation factors were calculated. Prevalence ratios of dental caries were estimated for each risk factor.

Results

The prevalence of clinical and self-reported caries (DMFT>1) was 66.5% (95%CI: 63.6%–69.3%) and 60.3% (95%CI: 58.8%–61.8%), respectively. Self-reports underestimated the prevalence of dental caries by 9.3% in comparison to clinical evaluations. The analysis of the validity of self-reports regarding the DMFT index indicated high sensitivity (81.8%; 95%CI: 78.7%–84.7%) and specificity (78.1%; 95%CI: 73.3%–82.4%) in relation to the gold standard (clinical evaluation). Both the clinical and self-reported evaluations were associated with gender, schooling and self-rated oral health. Clinical dental caries was associated with visits to the dentist in the previous year. Self-reported dental caries was associated with daily tooth brushing frequency.

Conclusions

Based on the present findings, self-reported information on dental caries using the DMFT index requires further studies prior to its use in the analysis of risk factors, but is valid for population-based health surveys with the aim of planning and monitoring oral health actions directed at adolescents.     

Sleep Duration Trajectories and Body Composition in Adolescents: Prospective Birth Cohort Study

We aimed to estimate the association between sleep duration trajectories and body composition in adolescents. We used data from participants of the 1993 Pelotas (Brazil) Birth Cohort Study who were later followed up at age 18 years (response rate of 81.3%). At the time, 3974 adolescents had complete data on body composition, which was assessed by air displacement plethysmography. Sleep duration was self-reported by participants at ages 11 and 18 years. Analyses were sex-stratified. The mean sleep duration at 11 years was 9.7 (SD 1.4) and 8.4 (SD 1.9) at 18 years. Sleep duration was dichotomized as inadequate (<8 hours/day) or adequate (≥8 hours/day). Mean body mass, fat mass, and fat-free mass indices at 18 years were 23.4 kg/m² (SD 4.5), 6.1 kg/m² (SD 3.9) and 17.3 kg/m² (SD 2.5), respectively. Girls who reported inadequate sleep duration at 11 years of age, but adequate sleep duration at 18, on average experienced an increase in body mass index (β = 0.39 z-scores; 95% CI 0.13, 0.65), fat mass index (β = 0.30 z-scores; 95% CI 0.07, 0.53), and fat-free mass index (β = 0.24 z-scores; 95% CI 0.08, 0.39) compared to those who had adequate sleep duration at both time points. The results suggest that changes in sleep duration across adolescence may impact body composition in later adolescence and that this may differ by sex.     

Association between Birth Interval and Cardiovascular Outcomes at 30 Years of Age: A Prospective Cohort Study from Brazil

Background

Birth interval is an important and potentially modifiable factor that is associated with child health. Whether an association exists with longer-term outcomes in adults is less well known.

Methods

Using the 1982 Pelotas (Brazil) Birth Cohort Study, the association of birth interval with markers of cardiovascular health at 30 years of age was examined. Multivariable linear regression was used with birth interval as a continuous variable and categorical variable, and effect modification by gender was explored.

Results

Birth interval and cardiovascular data were present for 2,239 individuals. With birth interval as a continuous variable, no association was found but stratification by gender tended to show stronger associations for girls. When compared to birth intervals of <18 months, as binary variable, longer intervals were associated with increases in height (1.6 cm; 95% CI: 0.5, 2.8) and lean mass (1.7 kg; 95% CI: 0.2, 3.2). No difference was seen with other cardiovascular outcomes.

Conclusions

An association was generally not found between birth interval and cardiovascular outcomes at 30 years of age, though some evidence existed for differences between males and females and for an association with height and lean mass for birth intervals of 18 months and longer.     

Birth Weight,Growth and Feeding Pattern in Early Infancy Predict Overweight/Obesity Status at Two Years of Age: A Birth Cohort Study of Chinese Infants

Objectives

To investigate the early determinants of overweight and obesity status at age two years.

Methods

A total of 1098 healthy neonates (563 boys and 535 girls) were involved in this community-based prospective study in China. Data on body weight and length were collected at birth, the 3^rd and 24^th month. A self-administered questionnaire was used to collect data on social demography and feeding patterns of children, etc. Three multivariable logistic regression models were employed to make various comparisons of weight status, i.e., model 1 (obesity vs. non-obesity), model 2 (combined overweight and obesity vs. normal weight, and model 3 (obesity, overweight and normal weight).

Results

Prevalences of overweight/obesity (95^th >BMI ≥85^th p and BMI ≥95^th p, referring to WHO BMI standards) at 2 years of age are 15.8%/11.2% for boys and 12.9%/9.0% for girls, respectively. Being born with macrosomia (OR: 1.80–1.88), relatively greater BMI increment in the first 3 months (OR: 1.15–1.16) and bottle emptying by encouragement at age two (OR: 1.30–1.57) were found in all three models to be significant risk factors for higher BMI status at 2 years. Pre-pregnancy maternal BMI (OR: 1.09–1.12), paternal BMI (OR: 1.06), and mixed breastfeeding (OR: 1.54–1.57) or formula feeding (OR: 1.90–1.93) in the first month were identified as significant in models 2 and 3. Child-initiated bottle emptying at age two was observed to increase the risk of obesity by 1.31 times but only in model 1.

Conclusion

Fetal and early postnatal growth and feeding pattern appear to have significant impacts on early childhood overweight and obesity status independent of parental BMI. Policy-based and multidisciplinary approaches to promote breastfeeding and enhancement of feeding skills of care takers may be promising intervention strategies.     

Genetic Determinants of Height Growth Assessed Longitudinally from Infancy to Adulthood in the Northern Finland Birth Cohort 1966

Recent genome-wide association (GWA) studies have identified dozens of common variants associated with adult height. However, it is unknown how these variants influence height growth during childhood. We derived peak height velocity in infancy (PHV1) and puberty (PHV2) and timing of pubertal height growth spurt from parametric growth curves fitted to longitudinal height growth data to test their association with known height variants. The study consisted of N=3,538 singletons from the prospective Northern Finland Birth Cohort 1966 with genotype data and frequent height measurements (on average 20 measurements per person) from 0–20 years. Twenty-six of the 48 variants tested associated with adult height (p<0.05, adjusted for sex and principal components) in this sample, all in the same direction as in previous GWA scans. Seven SNPs in or near the genes HHIP, DLEU7, UQCC, SF3B4/SV2A, LCORL, and HIST1H1D associated with PHV1 and five SNPs in or near SOCS2, SF3B4/SV2A, C17orf67, CABLES1, and DOT1L with PHV2 (p<0.05). We formally tested variants for interaction with age (infancy versus puberty) and found biologically meaningful evidence for an age-dependent effect for the SNP in SOCS2 (p=0.0030) and for the SNP in HHIP (p=0.045). We did not have similar prior evidence for the association between height variants and timing of pubertal height growth spurt as we had for PHVs, and none of the associations were statistically significant after correction for multiple testing. The fact that in this sample, less than half of the variants associated with adult height had a measurable effect on PHV1 or PHV2 is likely to reflect limited power to detect these associations in this dataset. Our study is the first genetic association analysis on longitudinal height growth in a prospective cohort from birth to adulthood and gives grounding for future research on the genetic regulation of human height during different periods of growth.     

Carotid Intima-Media Thickness at Age 30, Birth Weight,Accelerated Growth during Infancy and Breastfeeding: A Birth Cohort Study in Southern Brazil

Objective

To examine the relationship between carotid intima-media thickness (IMT) at age 30 and birth characteristics, growth during infancy, and breastfeeding duration, among subjects who have been prospectively followed since birth.

Methods and Results

In 1982, all births in the city of Pelotas, southern Brazil, were identified and those children (n = 5,914) whose families lived in the urban area of the city have been followed and evaluated at several time points. The cohort participants were evaluated in 2012–13, and IMT was measured at the posterior wall of the right and left common carotid arteries in longitudinal planes using ultrasound imaging. We obtained valid IMT measurements for 3,188 individuals. Weight-for-age z-score (WAZ) at age 2 years, weight-for-height z-score (WHZ) at age 4, height-for-age z-score (HAZ) at 4 years, WAZ at age 4 and relative conditional weight at 4 years were positively associated with IMT, even after controlling for confounding variables. The beta-coefficient associated with ≥1 s.d. WAZ at age 2 (compared to those with a <–1 s.d.) was 3.62 μm (95% CI 0.86 to 6.38). The beta-coefficient associated with ≥1 s.d. WHZ at 4 (in relation to <–1 s.d) was 3.83 μm (95% CI 0.24 to 7.42). For HAZ at 4, the beta-coefficient for ≥1 s.d. in relation to <–1 s.d. was 4.19 μm (95% CI 1.14 to 7.25). For WAZ at 4, the beta-coefficient associated with ≥1 s.d. in relation to <–1 s.d. was 4.28 μm (95% CI 1.59 to 6.97). The beta-coefficient associated with conditional weight gain at age 2–4 was 1.26 μm (95% CI 0.49 to 2.02).

Conclusion

IMT at age 30 was positively associated with WAZ at age 2 years, WHZ at age 4, HAZ at age 4, WAZ at age 4 and conditional weight gain at age 4 years.     

Associations of Aging and Birth Cohort with Body Mass Index in a Biethnic Cohort

Objective: To examine associations of aging and birth cohort with body mass index (BMI) in a biethnic cohort. Research Methods and Procedures: This was a longitudinal closed cohort study of 14, 500 white and African‐American men and women, 45 to 64 years of age, followed for 9 years. Aging was defined as the length of the interval in years between baseline and following visits. Birth cohort was defined by the year in which participants were born. Mixed model analyses were used to examine associations of aging, birth cohort, and BMI in four ethnicity‐gender groups. Results: We found that aging was associated with an increase in BMI in white and African‐American men and women. The associations between aging and BMI were stronger in the younger birth cohorts. Except for white women, younger birth cohort was associated with a higher BMI. After adjusting for aging, birth cohort was associated with an increase in BMI of 0.1 kg/m² [95% confidence interval (95% CI): ?0.1, 0.3] among white women. The corresponding values for African‐American women, white men, and African‐American men are 0.5 kg/m² (95% CI: 0.1, 0.9), 0.6 kg/m² (95% CI: 0.4, 0.8), and 0.6 kg/m² (95% CI: 0.2, 1.0), respectively. Discussion: Our analyses show that, in all except white women, people in this age range who were born later have a higher BMI at the same attained age. In all groups, people who are born later gained more weight as they aged. In general, subjects ages 45 to 64 years gained weight as they aged 9 years.     

Risk Factors for Soil-Transmitted Helminth Infections during the First 3 Years of Life in the Tropics; Findings from a Birth Cohort

Background

Soil-transmitted helminths (STH) infect more than 2 billion humans worldwide, causing significant morbidity in children. There are few data on the epidemiology and risk factors for infection in pre-school children. To investigate risk factors for infection in early childhood, we analysed data prospectively collected in the ECUAVIDA birth cohort in Ecuador.

Methods and Findings

Children were recruited at birth and followed up to 3 years of age with periodic collection of stool samples that were examined microscopically for STH parasites. Data on social, demographic, and environmental risk factors were collected from the mother at time of enrolment. Associations between exposures and detection of STH infections were analysed by multivariable logistic regression. Data were analysed from 1,697 children for whom a stool sample was obtained at 3 years. 42.3% had at least one STH infection in the first 3 years of life and the most common infections were caused by A. lumbricoides (33.2% of children) and T. trichiura (21.2%). Hookworm infection was detected in 0.9% of children. Risk of STH infection was associated with factors indicative of poverty in our study population such as Afro-Ecuadorian ethnicity and low maternal educational level. Maternal STH infections during pregnancy were strong risk factors for any childhood STH infection, infections with either A. lumbricoides or T. trichiura, and early age of first STH infection. Children of mothers with moderate to high infections intensities with A. lumbricoides were most at risk.

Conclusions

Our data show high rates of infection with STH parasites during the first 3 years of life in an Ecuadorian birth cohort, an observation that was strongly associated with maternal STH infections during pregnancy. The targeted treatment of women of childbearing age, in particular before pregnancy, with anthelmintic drugs could offer a novel approach to the prevention of STH infections in pre-school children.     

The Effect of Fetal and Childhood Growth over Depression in Early Adulthood in a Southern Brazilian Birth Cohort

Background

Poor nutrition and growth during fetal life and childhood might be associated with depression in adulthood; however, studies evaluating these associations present controversial results, especially when comparing studies using different proxies for fetal growth. We evaluated the association of fetal and childhood growth/nutrition with depression, in adulthood, using different approaches and measurement methods.

Method

In 1982, hospital births (n = 5914) in Pelotas, southern Brazil, were examined and have been prospectively followed. At 30 years, the presence of major depression and depressive symptoms severity was evaluated using the Mini International Neuropsychiatric Interview (MINI) and Beck Depression Inventory (BDI-II). The present study assessed their association with birth weight, premature birth, small for gestational age (SGA), stunting and conditional growth during childhood.

Results

At 30 years, 3576 individuals were evaluated and 7.9% had major depression. Low birth weight (PR = 1.01 95%CI [0.64–1.60]), having been born SGA (PR = 0.87 95%CI [0.64–1.19]) and premature birth (PR = 1.22 95%CI [0.72–2.07]) were not associated with major depression in multivariable models. However, those born SGA who were also stunted in childhood had a higher prevalence of major depression (PR = 1.87 95%CI [1.06–3.29]) and greater odds of scoring a higher level of depression in the BDI-II (OR = 2.18 95%CI [1.34–3.53]).

Conclusion

In this Brazilian cohort of young adults, those born SGA who were also stunted during childhood had a higher risk of depression in adulthood. Our results show that the effect of growth impairment on depression is cumulative.     

Trajectories of Sensory Over-Responsivity from Early to Middle Childhood: Birth and Temperament Risk Factors

Sensory over-responsivity, a subtype of sensory modulation disorder, is characterized by extreme negative reactions to normative sensory experiences. These over-reactions can interfere with daily activities and cause stress to children and their families. The etiology and developmental course of sensory over-responsivity is still largely unknown. We measured tactile and auditory over-responsivity in a population-based, typically developing sample of twins (N=978) at age two years via a caregiver report temperament questionnaire and again at age seven years via a sensory over-responsivity symptom inventory. Participating twins were treated as singletons although all analyses controlled for clustering within families. Children were divided into four trajectory groups based on risk status at both ages: low symptom (N=768), remitted (N=75), late-onset (N=112), and chronic (N=24). A subset of children who screened positive for SOR in toddlerhood (N = 102) took part in a pilot study focused on sensory over-responsivity at four years of age. Children in the chronic group had more severe symptoms of sensory sensitivity at age four years, including more motion sensitivity, than the other trajectory groups. Children in the chronic group had a younger gestational age and were more likely to be low birth-weight than the low symptom group. Differences between remitted and late-onset groups and the low-symptoms group were inconsistent across measures. Sensory over-responsivity was modestly correlated across ages (r = .22 for tactile over-responsivity and r = .11 for auditory over-responsivity), but symptoms were more stable among children born prematurely or who had more fearful and less soothable temperaments. A clear implication is that assessment over development may be necessary for a valid sensory processing disorder diagnosis, and a speculative implication is that sensory over-responsivity symptoms may be etiologically heterogeneous, with different causes of transient and stable symptoms.     

Early education and health outcomes of a 2001 U.S. Birth Cohort

This paper looks at health outcomes, health behaviors, and health screening with respect to participation in Early Childhood Care and Education. With information on health status at multiple periods in time, we are able to look at whether healthier children select into early childhood education (as measured by center-based preschool care and Head Start), as well as whether early childhood education has immediate and near-term effects on a range of health status measures. There is some evidence that child obesity is ameliorated by participation in center-based preschool or Head Start and this finding is supported by clear evidence of improved nutrition and increased levels of health screening. Effects on other health outcomes such as asthma, ear infections, and respiratory problems may be partially masked by unobserved heterogeneity.     

Associations between Skeletal Growth in Childhood and Cognitive Function in Mid-Life in a 53-Year Prospective Birth Cohort Study

Background

Several studies have found that shorter stature (height and limb length) in late life is associated with dementia and cognitive impairment. The extent to which childhood environment and early life cognitive function accounts for these associations is not clear.

Methods

We investigated associations of adult trunk height and leg length with cognitive function in middle age, analysing data from the MRC National Survey of Health and Development: a cohort followed from birth to age 53, 1677 of whom had data on all covariates. The four cognitive tests measured verbal ability, word list memory, verbal fluency and speed/concentration. Early life environmental measures included parental education, poverty, parental divorce, physical health, cognitive ability at age 15, own education and own adult social class.

Results

After adjusting for gender, shorter trunk length was associated with lower cognitive function on all four tests and shorter leg length with lower verbal intelligence and word list memory. These associations were only partially attenuated following adjustment for childhood adversity/health but were substantially accounted for by cognitive ability at age 15.

Conclusions

Shorter stature was associated with lower cognitive function at age 53, the majority of this association being accounted for by cognitive function at age 15. Reduced cognitive reserve may well account for later associations between anthropometric measures and dementia.     

Life Course Socioeconomic Position: Associations with Cardiac Structure and Function at Age 60-64 Years in the 1946 British Birth Cohort

Although it is recognized that risks of cardiovascular diseases associated with heart failure develop over the life course, no studies have reported whether life course socioeconomic inequalities exist for heart failure risk. The Medical Research Council’s National Survey of Health and Development was used to investigate associations between occupational socioeconomic position during childhood, early adulthood and middle age and measures of cardiac structure [left ventricular (LV) mass index and relative wall thickness (RWT)] and function [systolic: ejection fraction (EF) and midwall fractional shortening (mFS); diastolic: left atrial (LA) volume, E/A ratio and E/e’ ratio)]. Different life course models were compared with a saturated model to ascertain the nature of the relationship between socioeconomic position across the life course and each cardiac marker. Findings showed that models where socioeconomic position accumulated over multiple time points in life provided the best fit for 3 of the 7 cardiac markers: childhood and early adulthood periods for the E/A ratio and E/e’ ratio, and all three life periods for LV mass index. These associations were attenuated by adjustment for adiposity, but were little affected by adjustment for other established or novel cardio-metabolic risk factors. There was no evidence of a relationship between socioeconomic position at any time point and RWT, EF, mFS or LA volume index. In conclusion, socioeconomic position across multiple points of the lifecourse, particularly earlier in life, is an important determinant of some measures of LV structure and function. BMI may be an important mediator of these associations.     

Clinical Disorders in a Post War British Cohort Reaching Retirement: Evidence from the First National Birth Cohort Study

Background

The medical needs of older people are growing because the proportion of the older population is increasing and disease boundaries are widening. This study describes the distribution and clustering of 15 common clinical disorders requiring medical treatment or supervision in a representative British cohort approaching retirement, and how health tracked across adulthood.

Methods and Findings

The data come from a cohort of 2661 men and women, 84% of the target sample, followed since birth in England, Scotland and Wales in 1946, and assessed at 60–64 years for: cardio and cerebro-vascular disease, hypertension, raised cholesterol, renal impairment, diabetes, obesity, hypothyroidism, hyperthyroidism, anaemia, respiratory disease, liver disease, psychiatric problems, cancers, atrial fibrillation on ECG and osteoporosis. We calculated the proportions disorder-free, with one or more disorders, and the level of undiagnosed disorders; and how these disorders cluster into latent classes and relate to health assessed at 36 years. Participants had, on average, two disorders (range 0–9); only 15% were disorder-free. The commonest disorders were hypertension (54.3%, 95% CI 51.8%–56.7%), obesity (31.1%, 28.8%–33.5%), raised cholesterol (25.6%, 23.1–28.26%), and diabetes or impaired fasting glucose (25.0%, 22.6–27.5%). A cluster of one in five individuals had a high probability of cardio-metabolic disorders and were twice as likely than others to have been in the poorest health at 36 years. The main limitations are that the native born sample is entirely white, and a combination of clinical assessments and self reports were used.

Conclusions

Most British people reaching retirement already have clinical disorders requiring medical supervision. Widening disease definitions and the move from a disease-based to a risk-based medical model will increase pressure on health services. The promotion of healthy ageing should start earlier in life and consider the individual''s ability to adapt to and self manage changes in health.     

Cognitive and Kidney Function: Results from a British Birth Cohort Reaching Retirement Age

Background

Previous studies have found associations between cognitive function and chronic kidney disease. We aimed to explore possible explanations for this association in the Medical Research Council National Survey of Health and Development, a prospective birth cohort representative of the general British population.

Methods

Cognitive function at age 60–64 years was quantified using five measures (verbal memory, letter search speed and accuracy, simple and choice reaction times) and glomerular filtration rate (eGFR) at the same age was estimated using cystatin C. The cross-sectional association between cognitive function and eGFR was adjusted for background confounding factors (socioeconomic position, educational attainment), prior cognition, and potential explanations for any remaining association (smoking, diabetes, hypertension, inflammation, obesity).

Results

Data on all the analysis variables were available for 1306–1320 study members (depending on cognitive measure). Verbal memory and simple and choice reaction times were strongly associated with eGFR. For example, the lowest quartile of verbal memory corresponded to a 4.1 (95% confidence interval 2.0, 6.2) ml/min/1.73 m² lower eGFR relative to the highest quartile. Some of this association was explained by confounding due to socioeconomic factors, but very little of it by prior cognition. Smoking, diabetes, hypertension, inflammation and obesity explained some but not all of the remaining association.

Conclusions

These analyses support the notion of a shared pathophysiology of impaired cognitive and kidney function at older age, which precedes clinical disease. The implications of these findings for clinical care and research are important and under-recognised, though further confirmatory studies are required.