Risk of type 2 diabetes and cumulative excess weight exposure in the Framingham Offspring Study

Association of cumulative excess weight and waist circumference exposure with transition from metabolically healthy obesity to metabolically unhealthy

BACKGROUND AND AIMS

The association between obesity severity and duration with the transition from metabolically healthy obese/overweight (MHO) phenotype to metabolically unhealthy obese (MUO) phenotype is not well understood.

METHODS AND RESULTS

This study includes the Tehran Lipid and Glucose Study participants who were initially classed as MHO. Cumulative excess weight (CEW) and cumulative excess waist circumference (CEWC) scores, which represent the accumulation of body mass index and waist circumference deviations from expected values over time (kg/m² ∗ y and cm ∗ y, respectively), were calculated until the transition from MHO to MUO or the end of follow-up. The sex-stratified association of CEW and CWEC with the transition from MHO to MUO was investigated by time-dependent Cox models, adjusting for confounders. Out of 2525 participants, 1732 (68.5%) were women. During 15 years of follow-up, 1886 (74.6%) participants transitioned from MHO to MUO. A significant association was found between CEW and CEWC quartiles with the development of MUO among women participants (fully adjusted hazard ratios in the fourth quartile of CEW and CEWC [95% (CI)]:1.65 [1.37-1.98] and [95% CI]: 1.83 [1.53-2.19]). There was no significant association between CEW and CEWC with the MHO transition to MUO among men participants.

CONCLUSION

Over 15 years of follow-up in TLGS, general and central obesity accumulation was associated with the increased transition from MHO to MUO among women participants. More research with a larger sample size is needed to confirm and explain why the results are different for men and women.

Comparison of the one-year outcomes of bariatric surgery in adolescents and young adults: a matched case-control study, Tehran Obesity Treatment Study (TOTS)

PURPOSES

The increasing use of bariatric surgery in adolescents has raised some concerns regarding the postoperative outcomes and the optimal time of surgery at young ages. However, no study has yet compared the weight loss and comorbidity resolution following bariatric surgery between adolescents and young adults.

METHODS

This study was conducted on a case group of adolescents (aged 11-18) and a control group of young adults (aged 19-29) undergoing bariatric surgery (sleeve gastrectomy or gastric bypass). The two groups were matched in terms of gender, body mass index (BMI), and surgery type and were assessed regarding the surgical outcomes at 1 year after surgery.

RESULTS

The baseline characteristics of the adolescents (n = 118, mean age: 17.0 ± 1.6 years) and young adults (n = 236, mean age: 25.2 ± 3.2 years) were similar, as well as surgery-associated complications. The mean loss of BMI (- 15.4 ± 3.6 vs. -15.8 ± 4.6 kg/m²) and 12-month percentage of excess weight loss (80.4 ± 20.1 vs. 80.2 ± 20.1%) were similar in the two groups. Both groups showed parallel reductions in the cardiovascular risk factors. The remission of hypertension, diabetes mellitus, and dyslipidemia was similar between the groups. The increase in the hemoglobin level and copper deficiency was greater in young adults, whereas the increase in ferritin deficiency was greater in adolescents.

CONCLUSION

Similar to young adults, bariatric surgery is an effective and safe method to achieve weight loss, resolve obesity-related comorbidities, and improve cardiovascular risk factors in the adolescents.

Age of obesity onset, cumulative obesity exposure over early adulthood and risk of type 2 diabetes

AIMS/HYPOTHESIS

Obesity is a risk factor for type 2 diabetes, yet little is known about how timing and cumulative exposure of obesity are related to disease risk. The aim of this study was to examine the associations between BMI trajectories, age of onset of obesity and obese-years (a product of degree and duration of obesity) over early adulthood and subsequent risk of type 2 diabetes.

METHODS

Women aged 18-23 years at baseline (n = 11,192) enrolled in the Australian Longitudinal Study on Women's Health (ALSWH) in 1996 were followed up about every 3 years via surveys for up to 19 years. Self-reported weights were collected up to seven times. Incident type 2 diabetes was self-reported. A growth mixture model was used to identify distinct BMI trajectories over the early adult life course. Cox proportional hazards regression models were used to examine the associations between trajectories and risk of diabetes.

RESULTS

One hundred and sixty-two (1.5%) women were newly diagnosed with type 2 diabetes during a mean of 16 years of follow-up. Six distinct BMI trajectories were identified, varying by different initial BMI and different slopes of increase. Initial BMI was positively associated with risk of diabetes. We also observed that age at onset of obesity was negatively associated with risk of diabetes (HR 0.87 [95% CI 0.79, 0.96] per 1 year increment), and number of obese-years was positively associated with diabetes (p for trend <0.0001).

CONCLUSIONS/INTERPRETATION

Our data revealed the importance of timing of obesity, and cumulative exposure to obesity in the development of type 2 diabetes in young women, suggesting that preventing or delaying the onset of obesity and reducing cumulative exposure to obesity may substantially lower the risk of developing diabetes.

Excess BMI Accelerates Islet Autoimmunity in Older Children and Adolescents

OBJECTIVE

Sustained excess BMI increases the risk of type 1 diabetes (T1D) in autoantibody-positive relatives without diabetes of patients. We tested whether elevated BMI also accelerates the progression of islet autoimmunity before T1D diagnosis.

RESEARCH DESIGN AND METHODS

We studied 706 single autoantibody-positive pediatric TrialNet participants (ages 1.6-18.6 years at baseline). Cumulative excess BMI (ceBMI) was calculated for each participant based on longitudinally accumulated BMI ≥85th age- and sex-adjusted percentile. Recursive partitioning analysis and multivariable modeling defined the age cut point differentiating the risk for progression to multiple positive autoantibodies.

RESULTS

At baseline, 175 children (25%) had a BMI ≥85th percentile. ceBMI range was -9.2 to 15.6 kg/m² (median -1.91), with ceBMI ≥0 kg/m² corresponding to persistently elevated BMI ≥85th percentile. Younger age increased the progression to multiple autoantibodies, with age cutoff of 9 years defined by recursive partitioning analysis. Although ceBMI was not significantly associated with progression from single to multiple autoantibodies overall, there was an interaction with ceBMI ≥0 kg/m², age, and HLA (P = 0.009). Among children ≥9 years old without HLA DR3-DQ2 and DR4-DQ8, ceBMI ≥0 kg/m² increased the rate of progression from single to multiple positive autoantibodies (hazard ratio 7.32, P = 0.004) and conferred a risk similar to that in those with T1D-associated HLA haplotypes. In participants <9 years old, the effect of ceBMI on progression to multiple autoantibodies was not significant regardless of HLA type.

CONCLUSIONS

These data support that elevated BMI may exacerbate islet autoimmunity prior to clinical T1D, particularly in children with lower risk based on age and HLA. Interventions to maintain normal BMI may prevent or delay the progression of islet autoimmunity.

Different Weight Histories and Risk of Incident Coronary Heart Disease and Stroke: Tehran Lipid and Glucose Study

Background

This study aimed to determine the association between different weight histories, including cumulative excess weight, cumulative excess waist circumference (WC), duration of general and central adiposity, current and maximum body mass index, and current and maximum WC, and incident coronary heart disease (CHD) and stroke.

Methods and Results

The study population consisted of 4398 adults aged ≥40 years without CHD or stroke at baseline. Associations between different weight histories and CHD and stroke were determined by multivariable time‐varying Cox regression models after adjustment for age, sex, and time‐varying confounders. Further adjustment was also done for mediators (eg, diabetes mellitus, hypercholesterolemia, and hypertension). During median follow‐up of 13.9 years, 718 incident CHD and 158 stroke events were documented. Multivariable adjusted hazard ratios (HRs) were calculated in the sex and confounder adjusted model for CHD per 1‐SD increase in cumulative excess weight (HR: 1.02; 95% confidence interval [CI], 0.96–1.07), cumulative excess WC (HR: 1.14; 95% CI, 1.04–1.24), duration of general adiposity (HR: 1.00; 95% CI, 0.92–1.08), duration of central adiposity (HR: 1.01; 95% CI, 0.93–1.09), current body mass index (HR: 1.03; 95% CI, 0.99–1.07), current WC (HR: 1.21; 95% CI, 1.11–1.32), maximum body mass index (HR: 1.01; 95% CI, 0.95–1.07), and maximum WC (HR: 1.17; 95% CI, 1.07–1.28). After further adjustment for mediators, current and maximum WC still showed a significant risk (HR: 1.13 [95% CI, 1.03–1.23] and 1.09 [95% CI, 1.00–1.20], respectively). Moreover, in the sex and confounder adjusted model, cumulative excess WC and maximum WC were associated with higher risk of stroke (hazard ratio: 1.21 [95% CI, 0.99–1.48] and 1.25 [95% CI, 1.02–1.55], respectively).

Conclusions

Exposure to cumulative excess weight and cumulative excess WC confers little additional risk beyond their current and maximum values. Even current and maximum WC were associated with incident CHD in the presence of obesity mediators, and the latter was a significant predictor of stroke in the presence of confounders.

Is incident type 2 diabetes associated with cumulative excess weight and abdominal adiposity? Tehran Lipid and Glucose Study

AIMS

To examine the association of the risk of incident type 2 diabetes (T2D) with cumulative excess weight (CEW) and cumulative excess waist circumference (CEWC) scores.

METHODS

Adults participants without T2D (n = 4635) aged  ≥20 years were included in the study. The differences between the body mass index (BMI) and waist circumference (WC) values and their normal references were calculated until the incident T2D. The CEW and CEWC scores represent the accumulation of BMI and WC deviations from normal values over time, i.e. (kg/m² × years and cm × years, respectively). Time-dependent Cox models, adjusting for confounders were used to examine the association between CEW/CEWC and the risk of T2D. Further multivariate analyses were performed to examine the association of CEW and CEWC with incident diabetes in baseline BMI and WC strata.

RESULTS

There were 503 incident cases of T2D over a median follow-up 9.38 years. The multivariate sex adjusted hazard ratios (HR) per one standard deviation (SD) increase in CEW and CEWC were 1.23 (95% CI: 1.15-1.32) and 1.41 (1.25-1.59), respectively. After further adjustment for baseline BMI and WC, no significant association was observed for CEW (1.02: 0.84-1.23) and CEWC (1.09: 0.93-1.28) and incident T2D. A strong association was found between CEW and CEWC with incident diabetes among overweight (2.12: 1.20-3.74) and centrally obese individuals (1.29: 1.10-1.51), respectively.

CONCLUSIONS

Generally, CEW and CEWC were not associated with risk of T2D, independent of baseline values for BMI and WC, respectively. Moreover, CEW and CEWC highlighted an increased risk among overweight and centrally obese participants for T2D.

Low Birth Weight, Cumulative Obesity Dose, and the Risk of Incident Type 2 Diabetes

BACKGROUND

Obesity history may provide a better understanding of the contribution of obesity to T2DM risk.

METHODS

17,634 participants from the 1958 National Child Development Study were followed from birth to 50 years. Cumulative obesity dose, a measure of obesity history, was calculated by subtracting the upper cut-off of the normal BMI from the actual BMI at each follow-up and summing the areas under the obesity dose curve. Hazard ratios (HRs) for diabetes were calculated using Cox regression analysis. Three separate models compared the predictive ability of cumulative obesity dose on diabetes risk with the time-varying BMI and last BMI.

RESULTS

In final models, 341 of 15,043 (2.27%) participants developed diabetes; male sex and low birth weight were significant confounding variables. Adjusted HRs were 1.080 (95% CI: 1.071, 1.088) per 10-unit cumulative obesity dose, 1.098 (95% CI: 1.080, 1.117) per unit of the time-varying BMI, and 1.146 (95% CI: 1.084, 1.212) per unit of the last BMI. Cumulative obesity dose provided the best predictive ability for diabetes.

CONCLUSIONS

Cumulative obesity dose is an improved method for evaluating the impact of obesity history on diabetes risk. The link between low birth weight and T2DM is strengthened by adjusting for cumulative obesity dose.

The Role of Age and Excess Body Mass Index in Progression to Type 1 Diabetes in At-Risk Adults

BACKGROUND

Given the global rise in both type 1 diabetes incidence and obesity, the role of body mass index (BMI) on type 1 diabetes pathophysiology has gained great interest. Sustained excess BMI in pediatric participants of the TrialNet Pathway to Prevention (PTP) cohort increased risk for progression to type 1 diabetes, but the effects of age and obesity in adults remain largely unknown.

OBJECTIVE

To determine the effect of age and sustained obesity on the risk for type 1 diabetes in adult participants in the TrialNet PTP cohort (i.e., nondiabetic autoantibody-positive relatives of patients with type 1 diabetes).

RESEARCH DESIGN AND METHODS

Longitudinally accumulated BMI >25 kg/m2 was calculated to generate a cumulative excess BMI (ceBMI) for each participant, with ceBMI values ≥0 kg/m2 and ≥5 kg/m2 representing sustained overweight or obese status, respectively. Recursive partitioning analysis yielded sex- and age-specific thresholds for ceBMI that confer the greatest risk for type 1 diabetes progression.

RESULTS

In this cohort of 665 adults (age 20 to 50 years; median follow-up, 3.9 years), 49 participants developed type 1 diabetes. Age was an independent protective factor for type 1 diabetes progression (hazard ratio, 0.95; P = 0.008), with a threshold of >35 years that reduced risk for type 1 diabetes. In men age >35 years and women age <35 years, sustained obesity (ceBMI ≥5 kg/m2) increased the risk for type 1 diabetes.

CONCLUSIONS

Age is an important factor for type 1 diabetes progression in adults and influences the impact of elevated BMI, indicating an interplay of excess weight, age, and sex in adult type 1 diabetes pathophysiology.

Excess BMI in Childhood: A Modifiable Risk Factor for Type 1 Diabetes Development?

OBJECTIVE

We aimed to determine the effect of elevated BMI over time on the progression to type 1 diabetes in youth.

RESEARCH DESIGN AND METHODS

We studied 1,117 children in the TrialNet Pathway to Prevention cohort (autoantibody-positive relatives of patients with type 1 diabetes). Longitudinally accumulated BMI above the 85th age- and sex-adjusted percentile generated a cumulative excess BMI (ceBMI) index. Recursive partitioning and multivariate analyses yielded sex- and age-specific ceBMI thresholds for greatest type 1 diabetes risk.

RESULTS

Higher ceBMI conferred significantly greater risk of progressing to type 1 diabetes. The increased diabetes risk occurred at lower ceBMI values in children <12 years of age compared with older subjects and in females versus males.

CONCLUSIONS

Elevated BMI is associated with increased risk of diabetes progression in pediatric autoantibody-positive relatives, but the effect varies by sex and age.

Long term trends and racial/ethnic disparities in the prevalence of obesity

Obesity is an epidemic associated with higher rates of hypertension, diabetes, and cardiovascular diseases. However, significant racial disparities in the prevalence of obesity have been reported. To evaluate racial disparities and trends in the prevalence of obesity and obesity-related diseases. A population-based retrospective cohort study utilized data from the 1985 to 2011 California Behavioral Risk Factor Survey. Trends in obesity prevalence were stratified by age, sex, race/ethnicity, and socioeconomic factors. Multivariate logistic regression models evaluated independent predictors of obesity. The prevalence of obesity in significantly increased from 1985 to 2011 (8.6 vs. 22.8%, p < 0.001). This increase was seen among men and women, and among all race/ethnic, age, and socioeconomic groups. Hypertension and diabetes also increased during this time period (hypertension 20.7-35.9%; diabetes 4.2-11.2%). Obesity prevalence was highest in blacks and Hispanics, and lowest in Asians (blacks 33.3%; Hispanics 28.8%; Asians 9.0%; p < 0.001). Obesity prevalence was associated with lower education level, lower income, and unemployment status. After adjustments for age, sex, co morbidities, and surrogates of socioeconomic status, the increased risk of obesity in blacks and Hispanics persisted (blacks OR 1.51; Hispanics OR 1.18), whereas Asians were less likely to be obese (OR 0.37). While the overall prevalence of obesity increased from 1985 to 2011, significant racial/ethnic disparities in obesity have developed, with the highest prevalence seen in blacks and Hispanics, and the lowest seen in Asians.

Body mass index in early and middle adult life: prospective associations with myocardial infarction, stroke and diabetes over a 30-year period: the British Regional Heart Study

OBJECTIVES

Adiposity in middle age is an established risk factor for cardiovascular disease and type 2 diabetes; less is known about the impact of adiposity from early adult life. We examined the effects of high body mass index (BMI) in early and middle adulthood on myocardial infarction (MI), stroke and diabetes risks.

DESIGN

A prospective cohort study.

PARTICIPANTS

7735 men with BMI measured in middle age (40-59 years) and BMI ascertained at 21 years from military records or participant recall.

PRIMARY AND SECONDARY OUTCOME MEASURES

30-year follow-up data for type 2 diabetes, MI and stroke incidence; Cox proportional hazards models were used to examine the effect of BMI at both ages on these outcomes, adjusted for age and smoking status.

RESULTS

Among 4846 (63%) men (with complete data), a 1 kg/m(2) higher BMI at 21 years was associated with a 6% (95% CI 4% to 9%) higher type 2 diabetes risk, compared with a 21% (95% CI 18% to 24%) higher diabetes risk for a 1 kg/m(2) higher BMI in middle age (hazard ratio (HR) 1.21, 95% CI 1.18 to 1.24). Higher BMI in middle age was associated with a 6% (95% CI 4% to 8%) increase in MI and a 4% (95% CI 1% to 7%) increase in stroke; BMI at 21 years showed no associations with MI or stroke risk.

CONCLUSIONS

Higher BMI at 21 years of age is associated with later diabetes incidence but not MI or stroke, while higher BMI in middle age is strongly associated with all outcomes. Early obesity prevention may reduce later type 2 diabetes risk, more than MI and stroke.

Cumulative Weight Exposure Is Associated with Different Weight Loss Strategies and Weight Loss Success in Adults Age 50 or Above

Objectives. To evaluate if cumulative weight exposure is associated with weight loss strategy choices and weight loss success. Methods. Data from the National Health and Nutrition Examination Survey were used; a total of 4,562 people age 50 years or older who reported trying to lose weight in the last year were studied. Cumulative weight exposure (CWE) score was defined as the sum of body mass index points above 25 kg/m(2) at the age of 25, 10 years ago, 1 year ago, and now. Weight loss strategies were self-reported and weight loss success was defined as reaching a 5% weight loss in the last year. Results. Chosen strategies for weight loss vary across tertiles of CWE. Participants in the highest CWE tertile were about 4 to 20 times more likely to lose at least 5% of body weight in the past year compared to those in the lowest CWE tertile (P < 0.05).  Discussion. Strategies used to lose weight and weight loss success using different weight loss strategies vary considerably across cumulative weight exposure. Thus, cumulative weight exposure might be a variable worth considering when intervening with this population.

Trajectory of body mass index before the development of type 2 diabetes in Japanese men: Toranomon Hospital Health Management Center Study 15

Aims/Introduction

We aimed to investigate the long-term trajectory of general adiposity assessed by the body mass index (BMI) before the onset of type 2 diabetes in Japanese individuals.

Materials and Methods

We retrospectively examined data on 1,553 Japanese men without diabetes. Mean BMI and incident cases of diabetes (diabetes indicated by fasting glucose concentrations ≥7.0 mmol/L, a self-reported history of clinician-diagnosed diabetes, or glycated hemoglobin ≥6.5% (≥48 mmol/mol) were assessed on an annual basis over a 10-year period after the baseline examination.

Results

Mean (standard deviation) BMI at the time of diagnosis was 24.4 kg/m² (3.1 kg/m²) among cases of diabetes (n = 191). An increasingly high BMI was associated with the early stage of the disease development, such as an 8- to 10-year prediagnosis period; individuals who developed diabetes experienced a prolonged and stable elevated BMI of ≥24.4 kg/m² over the 8 years before the diagnosis of diabetes. The mean BMI among the non-cases of diabetes did not exceed 23.2 kg/m² throughout the period.

Conclusions

These results suggested that Japanese men who eventually developed diabetes during the 10-year observation period were not characterized as obese, but had stable high-normal BMIs before the onset of diabetes. Previous evidence showed that values for glycemic markers rapidly increased before the development of diabetes; however, the present study showed a slight gain in BMI in the earlier stage of the natural history of diabetes followed by a prolonged period of overweight.