Midlife Body Mass Index Research Articles

Body mass index in early adulthood and dementia in late life: Findings from a pooled cohort.

To examine the independent association of body mass index (BMI) in early adulthood with dementia incidence among men and women. We studied 5104 older adults from the Cardiovascular Health Study (CHS) and the Health, Aging, and Body Composition (Health ABC) study. We imputed early adulthood and midlife BMI using a pooled parent cohort with complete adult lifespan coverage and previously established methods. Dementia was ascertained using criteria such as neuropsychological test battery, medical records, and dementia-related drug use. Pooled logistic regression (PLR) models were used. Compared to women with normal BMI in early adulthood, the odds of dementia were higher among both overweight (odds ratio [OR]=1.8; 95% confidence interval [CI]=1.31 to 2.54) and obese (OR=2.45; 95% CI=1.47 to 4.06) women, independent of mid- and late-life BMI. Similar relationship was observed in men. With the growing obesity epidemic among US adults, efforts aimed at reducing dementia may need to begin obesity prevention and treatment early in the life course.

Cardiovascular Risk Factor Trajectories Since Childhood and Cognitive Performance in Midlife: The Cardiovascular Risk in Young Finns Study.

Cardiovascular risk factors, such as high blood pressure, adverse serum lipids, and elevated body mass index in midlife, may harm cognitive performance. It is important to note that longitudinal accumulation of cardiovascular risk factors since childhood may be associated with cognitive performance already since childhood, but the previous evidence is scarce. We studied the associations of cardiovascular risk factors from childhood to midlife, their accumulation, and midlife cognitive performance. From 1980, a population-based cohort of 3596 children (3-18 years of age) have been repeatedly followed up for 31 years. Blood pressure, serum lipids, and body mass index were assessed in all follow-ups. Cardiovascular risk factor trajectories from childhood to midlife were identified using latent class growth mixture modeling. Cognitive testing was performed in 2026 participants 34 to 49 years of age using a computerized test. The associations of the cardiovascular risk factor trajectories and cognitive performance were studied for individual cardiovascular risk factors and cardiovascular risk factor accumulation. Consistently high systolic blood pressure (β=-0.262 SD [95% CI, -0.520 to -0.005]) and serum total cholesterol (β=-0.214 SD [95% CI, -0.365 to -0.064]) were associated with worse midlife episodic memory and associative learning compared with consistently low values. Obesity since childhood was associated with worse visual processing and sustained attention (β=-0.407 SD [95% CI, -0.708 to -0.105]) compared with normal weight. An inverse association was observed for the cardiovascular risk factor accumulation with episodic memory and associative learning (P for trend=0.008; 3 cardiovascular risk factors: β=-0.390 SD [95% CI, -0.691 to -0.088]), with visual processing and sustained attention (P for trend<0.0001; 3 cardiovascular risk factors: β=-0.443 SD [95% CI, -0.730 to -0.157]), and with reaction and movement time (P for trend=0.048; 2 cardiovascular risk factors: β=-0.164 SD [95% CI, -0.318 to -0.010]). Longitudinal elevated systolic blood pressure, high serum total cholesterol, and obesity from childhood to midlife were inversely associated with midlife cognitive performance. It is important to note that the higher the number of cardiovascular risk factors, the worse was the observed cognitive performance. Therefore, launching preventive strategies against cardiovascular risk factors beginning from childhood might benefit primordial promotion of cognitive health in adulthood.

Diffuse idiopathic skeletal hyperostosis in elderly Icelanders and its association with the metabolic syndrome: the AGES-Reykjavik Study

Objective: To describe the prevalence of diffuse idiopathic skeletal hyperostosis (DISH) in a large population-based study of elderly Icelanders, with particular reference to weight-related factors and the metabolic syndrome. Method: The study population comprised 5321 participants aged 68–96 years (2276 males, mean ± sd age 76 ± 5 , and 3045 females, age 77 ± 6) from the AGES-Reykjavik Study. DISH diagnosis was based on computed tomography (CT) scans, and interpreted strictly by the Resnick criteria and additional suggestions for CT interpretation by Oudkerk et al. Radiology readings were taken by a radiology resident and sample readings by two experienced radiologists. Results: A diagnosis of DISH was made in 13.7% of males and 2.8% of females. There was no association with age, but a strong association was seen with the metabolic syndrome [odds ratio (OR) 2.12, 95% confidence interval (CI) 1.69–2.64, p = 3.9 × 10−11]. Among the components of the metabolic syndrome, the association with DISH was significant for the insulin resistance criterion (OR 1.66, 95% CI 1.32–2.01, p < 0.001) and the body mass index (BMI) criterion (OR 2.16, 95% CI 1.70–2.74, p < 0.001). Other weight-related variables (midlife BMI, weight, and abdominal circumference) showed similar associations. Conclusions: This study, which to our knowledge is the largest published study on the prevalence of DISH, shows an association with the metabolic syndrome, particularly with the insulin resistance and BMI criteria. This is analogous with previous reports linking DISH with metabolic causes. In this age category, we did not observe any increase in prevalence with age.

Obesity Progression Between Young Adulthood and Midlife and Incident Arthritis: A Retrospective Cohort Study of US Adults.

To examine the association between weight change from young adulthood to midlife and the risk of incident arthritis. Using data from the National Health and Nutrition Examination Survey, we categorized participants into weight-change categories based on their recalled weight during young adulthood and midlife. We estimated the association of weight change and developing an arthritis condition over 10 years using adjusted Cox models. Findings were extrapolated to the US population to determine the proportion of incident arthritis cases that could be averted if the entire population maintained a normal body mass index (BMI) in young adulthood and midlife. Among our sample of adults who were ages 40-69 years at their midlife weight measure (n = 13,669), 3,603 developed an arthritis condition. Compared with adults who maintained a normal-normal BMI, the normal-overweight, normal-obese, overweight-obese, and obese-obese groups had a significantly elevated risk of incident arthritis conditions. The obese-overweight group had a lower risk of incident arthritis conditions compared with the obese-obese group and a comparable risk to the overweight-overweight group. Nearly one-fourth of incident arthritis cases, corresponding to 2.7 million individuals, would have been averted under the hypothetical scenario where all individuals maintained normal weight from young adulthood to midlife. Weight loss from young adulthood to midlife was associated with a substantially reduced risk of developing an arthritis condition. We found no evidence of residual risk from having been heavier earlier in life. Our findings highlight the critical need to expand obesity treatment and prevention to achieve meaningful reductions in the burden of arthritis.

Association of early life BMI with dementia risk: Findings from a pooled cohort analysis

AbstractBackgroundThe evidence about the timing and influence of some key cardiovascular risk factors, such as Body Mass Index (BMI), on the risk of Alzheimer disease and other dementias remains debatable. Studies have shown that high midlife BMI increases the risk of dementia, while high late life BMI may be protective; however, relatively little is known about the role of early life BMI on the risk of Alzheimer Disease and other dementias.MethodWe studied 5,104 older adults from two studies, the Cardiovascular Health Study (CHS, n=2,909) and the Health, Aging and Body Composition study (Health ABC, n=2,195) study. For CHS‐Health ABC older adults, we imputed early and midlife BMI, beginning at age 18, using linear mixed models applied to a pooled cohort which also included young and middle‐aged adults from CARDIA and MESA. BMI was then summarized by time‐weighted averages in early (ages 20‐49), mid (ages 50‐69), and late life (ages 70‐89). In CHS, dementia was adjudicated by an expert committee following a detailed neuropsychological test battery and neurological examination. In Health ABC, dementia diagnosis was determined based on hospitalization ICD codes, dementia‐related drugs and decline on the Modified Mini Mental State Examination. All analyses were sex stratified.ResultCHS‐Health ABC participants had a mean age of 72.6 years (SD=4.2) at enrollment, 18% were black and 56% were women. For women, dementia risk increased with higher early life BMI: it was 1.8 times higher among those who were overweight (OR=1.8; 95% CI=1.31‐2.54) and 2.5 times higher among those who were obese (OR=2.45; 95% CI=1.47‐4.06), from pooled logistic regression models adjusted for midlife and late life BMI. For men, dementia risk increased with higher early life (Obese OR=2.47; 95% CI=1.46‐4.19) and mid life BMI (Overweight OR=1.51; 95% CI=1.11‐2.05 and Obese OR=2.00; 95% CI=1.16‐3.42), in models also adjusted for late life BMI. For both women and men, dementia risk decreased with higher late life BMI.ConclusionOur study is the first to report heightened dementia risk with higher early life BMI, for both women and men. Accounting for early life BMI, we found no effect for midlife BMI on dementia risk among women.

Association of Midlife Cardiovascular Risk Factors With the Risk of Heart Failure Subtypes Later in Life

BackgroundIndependent associations between cardiovascular risk factor exposures during midlife and later life development of heart failure (HF) with preserved ejection fraction (HFpEF) versus reduced EF (HFrEF) have not been previously studied. MethodsWe pooled data from 4 US cohort studies (Atherosclerosis Risk in Communities, Cardiovascular Health, Health , Aging and Body Composition, and Multi-Ethnic Study of Atherosclerosis) and imputed annual risk factor trajectories for body mass index, systolic and diastolic blood pressure, low-density lipoprotein and high-density lipoprotein cholesterol, and glucose starting from age 40 years. Time-weighted average exposures to each risk factor during midlife and later life were calculated and analyzed for associations with the development of HFpEF or HFrEF. ResultsA total of 23,861 participants were included (mean age at first in-person visit, 61.8 ±1 0.2 years; 56.6% female). During a median follow-up of 12 years, there were 3666 incident HF events, of which 51% had EF measured, including 934 with HFpEF and 739 with HFrEF. A high midlife systolic blood pressure and low midlife high-density lipoprotein cholesterol were associated with HFrEF, and a high midlife body mass index, systolic blood pressure, pulse pressure, and glucose were associated with HFpEF. After adjusting for later life exposures, only midlife pulse pressure remained independently associated with HFpEF. ConclusionsMidlife exposure to cardiovascular risk factors are differentially associated with HFrEF and HFpEF later in life. Having a higher pulse pressure during midlife is associated with a greater risk for HFpEF but not HFrEF, independent of later life exposures.

Age at menarche and risk of vasomotor menopausal symptoms: a pooled analysis of six studies.

To examine the association between age at menarche and risk of vasomotor menopausal symptoms (VMS) and whether midlife body mass index (BMI) modified the association. A pooled analysis of six cohort studies. The International collaboration on the Life course Approach to reproductive health and Chronic disease Events (InterLACE). 18555 women from the UK, USA and Australia. VMS frequency data (never, rarely, sometimes and often) were harmonised from two studies (n=13602); severity data (never, mild, moderate and severe) from the other four studies (n=4953). Multinominal logistic regression models were used to estimate relative risk ratios (RRRs) and 95%CIs adjusted for confounders and incorporated study as random effects. Hot flushes and night sweats. Frequency data showed that early menarche ≤11years was associated with an increased risk of 'often' hot flushes (RRR 1.48, 95% CI 1.24-1.76) and night sweats (RRR 1.59, 95% CI 1.49-1.70) compared with menarche at ≥14years. Severity data showed similar results, but appeared less conclusive, with RRRs of 1.16 (95% CI 0.94-1.42) and 1.27 (95% CI 1.01-1.58) for 'severe' hot flushes and night sweats, respectively. BMI significantly modified the association as the risk associated with early menarche and 'often' VMS was stronger among women who were overweight or obese than those of normal weight, while this gradient across BMI categories was not as strong with the risk of 'severe' VMS. Early age at menarche is a risk factor for VMS, particularly for frequent VMS, but midlife BMI may play an important role in modifying this risk. Overweight and obesity exacerbate the risk of vasomotor symptoms associated with early menarche.

Colorectal cancer risk based on extended family history and body mass index.

Family history and body mass index (BMI) are well-known risk factors for colorectal cancer (CRC), however, their joint effects are not well described. Using linked data for genealogy, self-reported height and weight from driver's licenses, and the Utah Surveillance, Epidemiology, and End-Results cancer registry, we found that an increasing number of first-degree relatives (FDR) with CRC is associated with higher standardized incidence ratio (SIR) for overweight/obese probands but not for under/normal weight probands. For probands with two CRC-affected FDRs, the SIR = 1.91 (95% CI [0.52, 4.89]) for under/normal weight probands and SIR = 4.31 (95% CI [2.46, 7.00]) for overweight/obese probands. In the absence of CRC-affected FDRs, any number of CRC-affected SDRs did not significantly increase CRC risk for under/normal weight probands, but for overweight/obese probands with at least three CRC-affected SDRs the SIR = 2.68 (95% CI [1.29, 4.93]). In the absence of CRC-affected FDRs and SDRs, any number of CRC-affected third-degree relatives (TDRs) did not increase risk in under/normal weight probands, but significantly elevated risk for overweight/obese probands with at least two CRC-affected TDRs was observed; SIR = 1.32 (95% CI [1.04, 1.65]). For nonsyndromic CRC, maximum midlife BMI affects risk based on family history and should be taken into account for CRC risk communication when possible.

Age-dependent effects of body mass index across the adult life span on the risk of dementia: a cohort study with a genetic approach

BackgroundWhile a high body mass index (BMI) in midlife is associated with higher risk of dementia, high BMI in late-life may be associated with lower risk. This study combined genetic designs with longitudinal data to achieve a better understanding of this paradox.MethodsWe used longitudinal data from 22,156 individuals in the Swedish Twin Registry (STR) and 25,698 from the Health and Retirement Study (HRS). The STR sample had information about BMI from early adulthood through late-life, and the HRS sample from age 50 through late-life. Survival analysis was applied to investigate age-specific associations between BMI and dementia risk. To examine if the associations are influenced by genetic susceptibility to higher BMI, an interaction between BMI and a polygenic score for BMI (PGSBMI) was included in the models and results stratified into those with genetic predisposition to low, medium, and higher BMI. In the STR, co-twin control models were applied to adjust for familial factors beyond those captured by the PGSBMI.ResultsAt age 35–49, 5 units higher BMI was associated with 15% (95% CI 7–24%) higher risk of dementia in the STR. There was a significant interaction (p = 0.04) between BMI and the PGSBMI, and the association present only among those with genetic predisposition to low BMI (HR 1.38, 95% CI 1.08–1.78). Co-twin control analyses indicated genetic influences. After age 80, 5 units higher BMI was associated with 10–11% lower risk of dementia in both samples. There was a significant interaction between late-life BMI and the PGSBMI in the STR (p = 0.01), but not the HRS, with the inverse association present only among those with a high PGSBMI (HR 0.70, 95% CI 0.52–0.94). No genetic influences were evident from co-twin control models of late-life BMI.ConclusionsNot only does the association between BMI and dementia differ depending on age at BMI measurement, but also the effect of genetic influences. In STR, the associations were only present among those with a BMI in opposite direction of their genetic predisposition, indicating that the association between BMI and dementia across the life course might be driven by environmental factors and hence likely modifiable.

Associations of Nativity, Age at Migration, and Percent of Life in the U.S. with Midlife Body Mass Index and Waist Size in New York City Latinas.

Migration to the U.S. has been associated with increased body size and obesity risk in Latinas, but results for Caribbean immigrant women are limited and inconclusive. Emerging evidence also suggests that early-life environment associations with women’s midlife body mass index (BMI) may be different for larger and smaller women, but this has not been tested within migration life-course history. We examined the associations of nativity and migration timing with midlife body size in a sample of majority Caribbean Latinas and whether these associations varied across the body size distribution. We used interview data from 787 self-identified Latinas (ages 40–65 years) and assessed overall obesity using BMI (kg/m2) and central obesity based on waist circumference (WC, cm). We used linear and quantile regression to examine the association of migration history with BMI and WC and logistic regression for the probability of obesity. Foreign birthplace, later migration age, and lower percent of life in the U.S. were associated with lower BMI and WC means and lower odds of overall and central obesity. Quantile regression showed only inverse associations in the upper quantiles of BMI and WC. For example, relative to U.S.-born women, women living <50% of their lives in the U.S. had lower BMI in the 75th BMI percentile (β = −4.10, 95% CI: −6.75, −0.81), with minimal differences in the 25th (β = 0.04, 95% CI: −1.01, 0.96) and 50th BMI percentiles (β = −1.54, 95% CI: −2.90, 0.30). Our results support that migration to and increasing time in the U.S. are associated with greater body size in midlife Latina women, with stronger influences at higher body size distribution.

Trajectories of early to mid-life adulthood BMI and incident diabetes: the China Health and Nutrition Survey

IntroductionThis longitudinal study aims to characterize distinct body mass index (BMI) trajectories during early to mid-life adulthood and to explore the association between BMI change from young adulthood to midlife...

Adiposity, Weight Change, and Risk of Cognitive Impairment: The Singapore Chinese Health Study.

Few prospective studies with long duration of follow-up have assessed the relations of body mass index (BMI) and weight change with cognitive function, especially in Asian populations. To investigate whether BMI and weight change in midlife are associated with cognitive impairment in old age. We used data from 14,691 participants in the Singapore Chinese Health Study and computed weight change as the difference between weight reported at baseline (1993-1998) at mean age of 53.0 years and follow-up 1 (1999-2004) at mean age of 58.6 years. Cognitive impairment was determined using education-specific cut-offs of the Singapore Modified Mini-Mental State Examination at follow-up 3 (2014-2016) at mean age of 72.9 years. We used multivariable logistic regression models to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the associations. Obesity (as defined BMI ≥27.5 kg/m2) was associated with a higher risk of cognitive impairment at baseline (OR 1.33, 95% CI 1.12-1.58) and follow-up 1 (OR 1.30, 95% CI 1.10-1.54) compared to BMI of 18.5-22.9 kg/m2. Underweight (BMI <18.5 kg/m2) was not associated with a significant risk either at baseline (OR 0.91, 95% CI 0.73-1.13) or follow-up 1 (OR 1.05, 95% CI 0.85-1.28). Compared to participants with <5% weight change, the ORs (95% CIs) of cognitive impairment were 1.20 (1.03-1.41) for those with 5-9.9% weight loss, 1.53 (1.29-1.81) for ≥10% weight loss, 1.00 (0.85-1.17) for 5-9.9% weight gain, and 1.50 (1.28-1.75) for ≥10% weight gain. Obesity, weight loss, and excessive weight gain at midlife were associated with an increased risk of cognitive impairment at old age.

Polygenic Risk, Fitness, and Obesity in the Coronary Artery Risk Development in Young Adults (CARDIA) Study

Obesity is a major determinant of disease burden worldwide. Polygenic risk scores (PRSs) have been posited as key predictors of obesity. How a PRS can be translated to the clinical encounter (especially in the context of fitness, activity, and parental history of overweight) remains unclear. To quantify the relative importance of a PRS, fitness, activity, parental history of overweight, and body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) in young adulthood on BMI trends over 25 years. This population-based prospective cohort study at 4 US centers included white individuals and black individuals with assessments of polygenic risk of obesity, fitness, activity, and BMI in young adulthood (in their 20s) and up to 25 years of follow-up. Data collected between March 1985 and August 2011 were analyzed from April 25, 2019, to September 29, 2019. Body mass index at the initial visit and 25 years later. This study evaluated an obesity PRS from a recently reported study of 1608 white individuals (848 women [52.7%]) and 909 black individuals (548 women [60.3%]) across the United States. At baseline (year 0), mean (SD) overall BMI was 24.2 (4.5), which increased to 29.6 (6.9) at year 25. Among white individuals, the PRS (combined with age, sex, self-reported parental history of overweight, and principal components of ancestry) explained 11.9% (at year 0) and 13.6% (at year 25) of variation in BMI. Although the addition of fitness increased the explanatory capability of the model (24.0% variance at baseline and up to 18.1% variance in BMI at year 25), baseline BMI in young adulthood was the strongest factor, explaining 52.3% of BMI in midlife in combination with age, sex, and self-reported parental history of overweight. Accordingly, models that included baseline BMI (especially BMI surveillance over time) were better in predicting BMI at year 25 compared with the PRS. In fully adjusted models, the effect sizes for fitness and the PRS on BMI were comparable in opposing directions. The added explanatory capacity of the PRS among black individuals was lower than among white individuals. Among white individuals, addition of baseline BMI and surveillance of BMI over time was associated with improved precision of predicted BMI at year 25 (mean error in predicted BMI 0 kg/m2 [95% CI, -11.4 to 11.4] to 0 kg/m2 [95% CI, -8.5 to 8.5] for baseline BMI and mean error 0 kg/m2 [95% CI, -5.3 to 5.3] for BMI surveillance). Cardiorespiratory fitness in young adulthood and a PRS are modestly associated with midlife BMI, although future BMI is associated with BMI in young adulthood. Fitness has a comparable association with future BMI as does the PRS. Caution should be exercised in the widespread use of polygenic risk for obesity prevention in adults, and close clinical surveillance and fitness may have prime roles in limiting the adverse consequences of elevated BMI on health.

The Effect of Gestational Weight Gain Across Reproductive History on Maternal Body Mass Index in Midlife: The Study of Women's Health Across the Nation.

Background: Excessive weight gain during pregnancy is common and has been shown to be associated with increased long-term maternal weight. However, less is known on whether there is a cumulative effect of excessive gestational weight gain (GWG) over multiple pregnancies. Methods: Data from the Study of Women's Health Across the Nation were used, restricted to parous women with no history of stillbirth or premature birth. The effect of the number of excessive GWG pregnancies on body mass index (BMI) in midlife (age 42-53) was analyzed using multivariable linear regression. Fully adjusted models included parity, inadequate GWG, demographic, and behavioral characteristics. Results: The 1181 women included in this analysis reported a total of 2693 births. Overall, 466 (39.5%) were categorized as having at least one pregnancy with excessive GWG. The median BMI at midlife was 26.0 kg/m2 (interquartile range 22.5-31.1). In fully adjusted models, each additional pregnancy with excessive GWG was associated with 0.021 higher estimated log BMI (p = 0.031). Among women with 1-3 births, adjusted mean (95% confidence interval) BMI for those with 0, 1, 2, and 3 excessive GWG pregnancies was 25.4 (24.9-25.9), 26.8 (26.1-27.5), 27.5 (26.6-28.4), and 28.8 (27.3-30.5), respectively. Conclusions: In this multiethnic study of women with a history of term live births, the number of pregnancies with excessive GWG was associated with increased maternal BMI in midlife. Our findings suggest that prevention of excessive GWG at any point in a woman's reproductive history can have an impact on long-term maternal health.

EXAMINING CUMULATIVE INEQUALITY IN THE ASSOCIATION BETWEEN CHILDHOOD SES AND BMI FROM MIDLIFE TO OLD AGE

Socioeconomic status (SES) is among the strongest determinants of body mass index (BMI). For older populations, selection bias is a large barrier to assessing cumulative disadvantages. We investigated the extent to which childhood SES affects BMI from midlife to old age and gender differences in the association. Data come from Midlife in the U.S. We used latent growth models to estimate BMI trajectory over a period of 20 years and examined results under different missing data patterns. Compared to individuals from higher childhood SES, those from lower childhood SES have higher BMI in midlife and experience a faster increase in BMI between midlife and old age. The observed associations remain significant even after controlling for midlife SES. After addressing nonrandom selection, the gap in BMI between high and low childhood SES widens from midlife to old age for women. The findings provide new evidence of cumulative inequality among older adults.

Midlife Body Mass Index Trajectory and Risk of Frailty 8 Years Later in Taiwan.

Few studies have focused on weight change and frailty, especially in Asia. This research aimed to evaluate midlife body mass index (BMI) trajectory and assess its relationship with frailty 8 years later in Taiwan. A prospective cohort study. Data were retrieved from the Taiwan Longitudinal Study on Aging conducted from 1999 to 2007. The analysis was restricted to respondents aged between 50 to 69 years old, who were not frail in 1999 and were alive in 2007 (n=1609). Frailty was defined using the Fried criteria. The group-based model of trajectory was used to estimate BMI trajectories among elderly participants. Logistic regression analysis was used to examine the association between BMI change and frailty. Four trajectory classes were identified and each remained stable during the 8-year follow-up. There were 316 participants (20.3%) in the low-normal weight group (baseline BMI=20.38 kg/m2), 737 participants (44.7%) in the high-normal weight group (baseline BMI=23.22 kg/m2), 449 participants (28.4%) in the overweight group (baseline BMI=26.24 kg/m2), and 107 participants (6.6%) in the obesity group (baseline BMI=30.65 kg/m2). After adjustment for confounding factors, the low-normal weight group and obesity group were associated with increased frailty compared with the high-normal weight group. Our results showed that the BMI trajectories of midlife individuals tended to be constant and those in both the low-normal weight group and obesity group had an increased risk of developing frailty in later life. Therefore, an optimal weight-targeting strategy should be considered for Asian elderly individuals.

Examining Cumulative Inequality in the Association Between Childhood Socioeconomic Status and Body Mass Index From Midlife to Old Age.

Socioeconomic status (SES) is among the strongest determinants of body mass index (BMI), particularly for women. For older populations, selection bias due to attrition is a large barrier to assessing the accumulation of inequality. Under multiple missing data mechanisms, we investigated the extent to which childhood and midlife SES affects BMI from midlife to old age and gender differences in the association. Data come from a longitudinal national study of 2,345 U.S. adults aged 40-54 at baseline. We used latent growth models to estimate BMI trajectory over a period of 20 years. We examined results under different missing data patterns and applied methods that account for nonrandom-selection bias. Compared with individuals who had higher childhood SES, individuals who had lower childhood SES have higher BMI in midlife and experience a faster increase in BMI between midlife and old age. The observed associations remain significant even after controlling for midlife SES. After addressing nonrandom selection, the gap in BMI between high and low childhood SES widens from midlife to old age for women. The findings provide new evidence of cumulative inequality among older adults, documenting increasing BMI inequality from midlife to old age, particularly for women from low-SES families.

Pregnancy History as an Important Predictor of Body Mass Index (BMI) in 45–54 Year-old Women (P21-047-19)

ObjectivesIn mid-life, women have elevated risks of cardiovascular and metabolic diseases. Pregnancy causes substantial metabolic changes in women, but it is unclear whether these changes persist life-long. Thus, we investigated associations between pregnancy history and mid-life overweight/obesity, accounting for the menopausal transition. MethodsPre- and peri-menopausal women (ages 45–54, n = 772) in the Baltimore Mid-Life Women’s Health Study reported their demographics, health habits, and pregnancy history (numbers of live births/pregnancies and age at first birth/last pregnancy) via questionnaires. Height and weight were measured to calculate BMI. Multivariable logistic regression models assessed overall and stratified (by menopausal status) associations of pregnancy history and risk of mid-life overweight/obesity (BMI ≥ 25 kg/m2), controlling for race, employment, health, alcohol intake, smoking status, physical activity, and menopausal status (unstratified models). ResultsWomen had a median age of 48, 65% were pre- and 35% were peri-menopausal, 65% were white, 63% had graduated college, and 74% had a family income ≥$50,000. Mean (SD) BMI was 28.5 (7.4) kg/m2, and was higher in peri- vs. pre-menopausal women (29.8 vs. 27.8 kg/m2; P < 0.005). Ages at first birth or last pregnancy were not associated with mid-life BMI. Women whose pregnancies either did or did not result in a live birth had 44% (OR: 0.56; 95% CI: 0.32, 0.99; P < 0.05) and 59% (OR: 0.41; 95% CI: 0.19, 0.87; P < 0.05), respectively, lower odds of being overweight/obese at age 45–54 compared to women who had never been pregnant. However, in women who had been pregnant, the odds of being overweight/obese increased by 19% with every live birth (OR: 1.19; 95% CI: 1.02, 1.40; P < 0.05). In stratified analyses, these associations remained significant only in pre-menopausal women. ConclusionsIn pre-menopausal women, having a history of pregnancy appears to be protective against overweight/obesity, but the protective effects diminish with every live birth. In peri-menopausal women, pregnancy history was not related to BMI, suggesting the importance of other lifestyle or physiological factors in determining BMI during menopause. The discrete findings in pre- vs. peri-menopausal women warrant studies examining relationships of pregnancy history with BMI after menopause. Funding SourcesThis study was made possible by funding from NIH/NIEHS, USDA, and Michigan AgBioResearch.

Body mass index and kidney disease-related mortality in midlife: A nationwide cohort of 2.3 million adolescents

Objective This study aimed to evaluate the association of body mass index (BMI) in adolescence with mortality attributed to kidney disease. Methods In this study, 2,294,139 Jewish Israeli adolescents with measured weight and height at 17 years old during the military fitness assessment were analyzed with a follow-up extending up to 45 years. All kidney-related outcomes, coded by the Central Bureau of Statistics from death notifications as the underlying cause of death, were obtained by linkage. Cox hazards models were applied. Results During 42,297,007 person-years of follow-up (median 18.4 years), 226 deaths related to kidney disease were recorded. There was an increased risk for kidney-related death among adolescents with overweight and obesity with adjusted hazard ratios of 2.7 (95% CI: 1.8-3.9) and 8.4 (5.1-13.8), respectively, with BMI between 18.5 and 22.0 kg/m2 as the reference. A 15% increased risk for kidney-related mortality (1.11-1.19) per unit increment in BMI was observed. Furthermore, a multivariable spline model indicated a minimum risk for kidney-related mortality starting at BMI of 18.6 kg/m2 with significantly increased risk seen above values of 22.8 kg/m2 . The results withstood extensive sensitivity analyses, including stratification of kidney-related death attributed to acute, chronic, and total kidney disease. Conclusions Adolescent overweight and obesity are risk markers for kidney-related mortality over 4 decades.

The association between BMI and mortality using early adulthood BMI as an instrumental variable for midlife BMI

The article aims to describe the association between midlife body mass index (BMI) and cardiovascular disease (CVD)- and all-cause mortality, and to use early adulthood BMI as an instrumental variable for midlife BMI, in order to obtain an estimate less distorted by midlife confounders and reverse causality. Data from Norwegian health surveys (1974–2003) (midlife BMI, smoking, blood pressure, total cholesterol, heart rate), Military Conscription Records, National Tuberculosis Screenings (early adulthood BMI), National Educational Registry and Cause of Death Registry were linked. Participants with data on BMI in early adulthood and midlife were included (n = 148.886). Hazard Ratio (HR) for CVD mortality was higher in men with midlife obesity relative to normal weight (HR = 1.46(95% CI 1.25, 1.70). For all-cause mortality, HR was higher in those with obesity or underweight in midlife relative to normal weight (Men:HR = 1.19(95% CI 1.09, 1.29), HR = 2.49(95% CI 1.81, 3.43) Women:HR = 1.33(95% CI 1.13, 1.56), HR = 1.61(95% CI 1.22, 2.13)). In instrumental variable analyses, increased BMI became more strongly associated with CVD and all-cause mortality, and the increased risk of all-cause mortality among the underweight attenuated.