Body-Mass Index in 2.3 Million Adolescents and Cardiovascular Death in Adulthood

BACKGROUND

In light of the worldwide increase in childhood obesity, we examined the association between body-mass index (BMI) in late adolescence and death from cardiovascular causes in adulthood.

METHODS

We grouped data on BMI, as measured from 1967 through 2010 in 2.3 million Israeli adolescents (mean age, 17.3±0.4 years), according to age- and sex-specific percentiles from the U.S. Centers for Disease Control and Prevention. Primary outcomes were the number of deaths attributed to coronary heart disease, stroke, sudden death from an unknown cause, or a combination of all three categories (total cardiovascular causes) by mid-2011. Cox proportional-hazards models were used.

RESULTS

During 42,297,007 person-years of follow-up, 2918 of 32,127 deaths (9.1%) were from cardiovascular causes, including 1497 from coronary heart disease, 528 from stroke, and 893 from sudden death. On multivariable analysis, there was a graded increase in the risk of death from cardiovascular causes and all causes that started among participants in the group that was in the 50th to 74th percentiles of BMI (i.e., within the accepted normal range). Hazard ratios in the obese group (≥95th percentile for BMI), as compared with the reference group in the 5th to 24th percentiles, were 4.9 (95% confidence interval [CI], 3.9 to 6.1) for death from coronary heart disease, 2.6 (95% CI, 1.7 to 4.1) for death from stroke, 2.1 (95% CI, 1.5 to 2.9) for sudden death, and 3.5 (95% CI, 2.9 to 4.1) for death from total cardiovascular causes, after adjustment for sex, age, birth year, sociodemographic characteristics, and height. Hazard ratios for death from cardiovascular causes in the same percentile groups increased from 2.0 (95% CI, 1.1 to 3.9) during follow-up for 0 to 10 years to 4.1 (95% CI, 3.1 to 5.4) during follow-up for 30 to 40 years; during both periods, hazard ratios were consistently high for death from coronary heart disease. Findings persisted in extensive sensitivity analyses.

CONCLUSIONS

A BMI in the 50th to 74th percentiles, within the accepted normal range, during adolescence was associated with increased cardiovascular and all-cause mortality during 40 years of follow-up. Overweight and obesity were strongly associated with increased cardiovascular mortality in adulthood. (Funded by the Environment and Health Fund.).

Adolescent BMI trajectory and risk of diabetes versus coronary disease

BACKGROUND

The association of body-mass index (BMI) from adolescence to adulthood with obesity-related diseases in young adults has not been completely delineated.

METHODS

We conducted a prospective study in which we followed 37,674 apparently healthy young men for incident angiography-proven coronary heart disease and diabetes through the Staff Periodic Examination Center of the Israeli Army Medical Corps. The height and weight of participants were measured at regular intervals, with the first measurements taken when they were 17 years of age.

RESULTS

During approximately 650,000 person-years of follow-up (mean follow-up, 17.4 years), we documented 1173 incident cases of type 2 diabetes and 327 of coronary heart disease. In multivariate models adjusted for age, family history, blood pressure, lifestyle factors, and biomarkers in blood, elevated adolescent BMI (the weight in kilograms divided by the square of the height in meters; mean range for the first through last deciles, 17.3 to 27.6) was a significant predictor of both diabetes (hazard ratio for the highest vs. the lowest decile, 2.76; 95% confidence interval [CI], 2.11 to 3.58) and angiography-proven coronary heart disease (hazard ratio, 5.43; 95% CI, 2.77 to 10.62). Further adjustment for BMI at adulthood completely ablated the association of adolescent BMI with diabetes (hazard ratio, 1.01; 95% CI, 0.75 to 1.37) but not the association with coronary heart disease (hazard ratio, 6.85; 95% CI, 3.30 to 14.21). After adjustment of the BMI values as continuous variables in multivariate models, only elevated BMI in adulthood was significantly associated with diabetes (β=1.115, P=0.003; P=0.89 for interaction). In contrast, elevated BMI in both adolescence (β=1.355, P=0.004) and adulthood (β=1.207, P=0.03) were independently associated with angiography-proven coronary heart disease (P=0.048 for interaction).

CONCLUSIONS

An elevated BMI in adolescence--one that is well within the range currently considered to be normal--constitutes a substantial risk factor for obesity-related disorders in midlife. Although the risk of diabetes is mainly associated with increased BMI close to the time of diagnosis, the risk of coronary heart disease is associated with an elevated BMI both in adolescence and in adulthood, supporting the hypothesis that the processes causing incident coronary heart disease, particularly atherosclerosis, are more gradual than those resulting in incident diabetes. (Funded by the Chaim Sheba Medical Center and the Israel Defense Forces Medical Corps.).

Body mass index in 1.2 million adolescents and risk for end-stage renal disease

BACKGROUND

The relationship between adolescent body mass index (BMI) and future risk for end-stage renal disease (ESRD) is not fully understood, nor is it known the extent to which this association is limited to diabetic ESRD. We evaluated the association between BMI in adolescence and the risk for all-cause, diabetic, and nondiabetic ESRD.

METHODS

Medical data about 1 194 704 adolescents aged 17 years who had been examined for fitness for military service between January 1, 1967, and December 31, 1997, were linked to the Israeli ESRD registry in this nationwide population-based retrospective cohort study. Incident cases of treated ESRD between January 1, 1980, and May 31, 2010, were included. Cox proportional hazards models were used to estimate the hazard ratio (HR) for treated ESRD among study participants for their BMI at age 17 years, defined in accord with the US Centers for Disease Control and Prevention BMI for age and sex classification.

RESULTS

During 30 478 675 follow-up person-years (mean [SD], 25.51 [8.77] person-years), 874 participants (713 male and 161 female) developed treated ESRD, for an overall incidence rate of 2.87 cases per 100 000 person-years. Compared with adolescents of normal weight, overweight adolescents (85th to 95th percentiles of BMI) and obese adolescents (≥95th percentile of BMI) had an increased future risk for treated ESRD, with incidence rates of 6.08 and 13.40 cases per 100 000 person-years, respectively. In a multivariate model adjusted for sex, country of origin, systolic blood pressure, and period of enrollment in the study, overweight was associated with an HR of 3.00 (95% CI, 2.50-3.60) and obesity with an HR of 6.89 (95% CI, 5.52-8.59) for all-cause treated ESRD. Overweight (HR, 5.96; 95% CI, 4.41-8.06) and obesity (HR, 19.37; 95% CI, 14.13-26.55) were strong and independent risk factors for diabetic ESRD. Positive associations of overweight (HR, 2.17; 95% CI, 1.71-2.74) and obesity (HR, 3.41; 95% CI, 2.42-4.79) with nondiabetic ESRD were also documented.

CONCLUSIONS

Overweight and obesity in adolescents were associated with significantly increased risk for all-cause treated ESRD during a 25-year period. Elevated BMI constitutes a substantial risk factor for diabetic and nondiabetic ESRD.

Persistent asymptomatic isolated microscopic hematuria in Israeli adolescents and young adults and risk for end-stage renal disease

CONTEXT

Few data are available on long-term outcomes among adolescents and young adults with persistent asymptomatic isolated microscopic hematuria.

OBJECTIVE

To evaluate the risk of end-stage renal disease (ESRD) in adolescents and young adults with persistent asymptomatic isolated microscopic hematuria.

DESIGN, SETTING, AND PARTICIPANTS

Nationwide, population-based, retrospective cohort study using medical data from 1,203,626 persons aged 16 through 25 years (60% male) examined for fitness for military service between 1975 and 1997 were linked to the Israeli treated ESRD registry. Incident cases of treated ESRD from January 1, 1980, to May 31, 2010, were included. Cox proportional hazards models were used to estimate the hazard ratio (HR) of treated ESRD among those diagnosed as having persistent asymptomatic isolated microscopic hematuria.

MAIN OUTCOME MEASURES

Treated ESRD onset, defined as the date of initiation of dialysis treatment or the date of renal transplantation, whichever came first.

RESULTS

Persistent asymptomatic isolated microscopic hematuria was diagnosed in 3690 of 1,203,626 eligible individuals (0.3%). During 21.88 (SD, 6.74) years of follow-up, treated ESRD developed in 26 individuals (0.70%) with and 539 (0.045%) without persistent asymptomatic isolated microscopic hematuria, yielding incidence rates of 34.0 and 2.05 per 100,000 person-years, respectively, and a crude HR of 19.5 (95% confidence interval [CI], 13.1-28.9). A multivariate model adjusted for age, sex, paternal country of origin, year of enrollment, body mass index, and blood pressure at baseline did not substantially alter the risk associated with persistent asymptomatic isolated microscopic hematuria (HR, 18.5 [95% CI, 12.4-27.6]). A substantially increased risk for treated ESRD attributed to primary glomerular disease was found for individuals with persistent asymptomatic isolated microscopic hematuria compared with those without the condition (incidence rates, 19.6 vs 0.55 per 100,000 person-years, respectively; HR, 32.4 [95% CI, 18.9-55.7]). The fraction of treated ESRD attributed to microscopic hematuria was 4.3% (95% CI, 2.9%-6.4%).

CONCLUSION

Presence of persistent asymptomatic isolated microscopic hematuria in persons aged 16 through 25 years was associated with significantly increased risk of treated ESRD for a period of 22 years, although the incidence and absolute risk remain quite low.

History of Childhood Kidney Disease and Risk of Adult End-Stage Renal Disease

BACKGROUND

The long-term risk associated with childhood kidney disease that had not progressed to chronic kidney disease in childhood is unclear. We aimed to estimate the risk of future end-stage renal disease (ESRD) among adolescents who had normal renal function and a history of childhood kidney disease.

METHODS

We conducted a nationwide, population-based, historical cohort study of 1,521,501 Israeli adolescents who were examined before compulsory military service in 1967 through 1997; data were linked to the Israeli ESRD registry. Kidney diseases in childhood included congenital anomalies of the kidney and urinary tract, pyelonephritis, and glomerular disease; all participants included in the primary analysis had normal renal function and no hypertension in adolescence. Cox proportional-hazards models were used to estimate the hazard ratio for ESRD associated with a history of childhood kidney disease.

RESULTS

During 30 years of follow-up, ESRD developed in 2490 persons. A history of any childhood kidney disease was associated with a hazard ratio for ESRD of 4.19 (95% confidence interval [CI], 3.52 to 4.99). The associations between each diagnosis of kidney disease in childhood (congenital anomalies of the kidney and urinary tract, pyelonephritis, and glomerular disease) and the risk of ESRD in adulthood were similar in magnitude (multivariable-adjusted hazard ratios of 5.19 [95% CI, 3.41 to 7.90], 4.03 [95% CI, 3.16 to 5.14], and 3.85 [95% CI, 2.77 to 5.36], respectively). A history of kidney disease in childhood was associated with younger age at the onset of ESRD (hazard ratio for ESRD among adults <40 years of age, 10.40 [95% CI, 7.96 to 13.59]).

CONCLUSIONS

A history of clinically evident kidney disease in childhood, even if renal function was apparently normal in adolescence, was associated with a significantly increased risk of ESRD, which suggests that kidney injury or structural abnormality in childhood has long-term consequences.

Progression of normotensive adolescents to hypertensive adults: a study of 26,980 teenagers

Although prehypertension at adolescence is accepted to indicate increased future risk of hypertension, large-scale/long follow-up studies are required to better understand how adolescent blood pressure (BP) tracks into young adulthood. We studied 23 191 male and 3789 female adolescents from the Metabolic Lifestyle and Nutrition Assessment in Young Adults cohort (mean age: 17.4 years) with BP <140/90 mm Hg at enrollment or categorized by current criteria for pediatric BP and body mass index (BMI) values. Participants were prospectively followed up with repeated BP measurements between ages 25 and 42 years and retrospectively between ages 17 and 25 years for the incidence of hypertension. We identified 3810 new cases of hypertension between ages 17 and 42 years. In survival analyses, the cumulative risk of hypertension between ages 17 and 42 years was 3 to 4 times higher in men than in women. Using Cox regression models adjusted for age, BMI, and stratified by baseline BP, the hazard ratio of hypertension increased gradually across BP groups within the normotensive range at age 17 years, without a discernible threshold effect, reaching a hazard ratio of 2.50 (95% CI: 1.75 to 3.57) for boys and 2.31 (95% CI: 0.71 to 7.60) for girls in the group with BP at 130 to 139/85 to 89 mm Hg. BMI at age 17 years was strongly associated with future risk of hypertension even when adjusted to BP at age 17 years, particularly in boys. Yet, BMI at age 30 years attenuated this association, more evidently in girls. In conclusion, BP at adolescence, even in the low-normotensive range, linearly predicts progression to hypertension in young adulthood. This progression and the apparent interaction between BP at age 17 years and BMI at adolescence and at adulthood are sex dependent.

Adolescent Obesity and Early-Onset Type 2 Diabetes

OBJECTIVE

Type 2 diabetes (T2D) is increasingly diagnosed at younger ages. We investigated the association of adolescent obesity with incident T2D at early adulthood.

RESEARCH DESIGN AND METHODS

A nationwide, population-based study evaluated 1,462,362 adolescents (59% men, mean age 17.4 years) during 1996-2016. Data were linked to the Israeli National Diabetes Registry. Weight and height were measured at study entry. Cox proportional models were applied.

RESULTS

During 15,810,751 person-years, 2,177 people (69% men) developed T2D (mean age at diagnosis 27 years). There was an interaction among BMI, sex, and incident T2D (P _interaction = 0.023). In a model adjusted for sociodemographic variables, the hazard ratios for diabetes diagnosis were 1.7 (95% CI 1.4-2.0), 2.8 (2.3-3.5), 5.8 (4.9-6.9), 13.4 (11.5-15.7), and 25.8 (21.0-31.6) among men in the 50th-74th percentile, 75th-84th percentile, overweight, mild obesity, and severe obesity groups, respectively, and 2.2 (1.6-2.9), 3.4 (2.5-4.6), 10.6 (8.3-13.6), 21.1 (16.0-27.8), and 44.7 (32.4-61.5), respectively, in women. An inverse graded relationship was observed between baseline BMI and mean age of T2D diagnosis: 27.8 and 25.9 years among men and women with severe obesity, respectively, and 29.5 and 28.5 years among low-normal BMI (5th-49th percentile; reference), respectively. The projected fractions of adult-onset T2D that were attributed to high BMI (≥85th percentile) at adolescence were 56.9% (53.8-59.9%) and 61.1% (56.8-65.2%) in men and women, respectively.

CONCLUSIONS

Severe obesity significantly increases the risk for incidence of T2D in early adulthood in both sexes. The rise in adolescent severe obesity is likely to increase diabetes incidence in young adults in coming decades.

White blood cells count and incidence of type 2 diabetes in young men

OBJECTIVE

Association between white blood cell (WBC) count and diabetes risk has been recently suggested. We assessed whether WBC count is an independent risk factor for diabetes incidence among young healthy adults.

RESEARCH DESIGN AND METHODS

WBC count was measured in 24,897 young (mean age 30.8 ± 5.36 years), normoglycemic men with WBC range of 3,000 to 12,000 cells/mm(3). Participants were periodically screened for diabetes during a mean follow-up of 7.5 years.

RESULTS

During 185,354 person-years of follow-up, diabetes was diagnosed in 447 subjects. A multivariate model adjusted for age, BMI, family history of diabetes, physical activity, and fasting glucose and triglyceride levels revealed a 7.6% increase in incident diabetes for every increment of 1,000 cells/mm(3) (P = 0.046). When grouped in quintiles, a baseline WBC count above 6,900 cells/mm(3) had an independent 52% increase in diabetes risk (hazard ratio 1.52 [95% CI 1.06-2.18]) compared with the lowest quintile (WBC <5,400 cells/mm(3)). Men at the lowest WBC quintile were protected from diabetes incidence even in the presence of overweight, family history of diabetes, or elevated triglyceride levels. After simultaneous control for risk factors, BMI was the primary contributor of the variation in multivariate models (P < 0.001), followed by age and WBC count (P < 0.001), and family history of diabetes and triglyceride levels (P = 0.12).

CONCLUSIONS

WBC count, a commonly used and widely available test, is an independent risk factor for diabetes in young men at values well within the normal range.

Diabetes risk among overweight and obese metabolically healthy young adults

OBJECTIVE

To determine diabetes incidence over time among obese young adults without metabolic risk factors.

RESEARCH DESIGN AND METHODS

Incident diabetes during a median follow-up of 6.1 years was assessed among 33,939 young men (mean age 30.9 ± 5.2 years) of the Metabolic, Lifestyle and Nutrition Assessment in Young Adults cohort who were stratified for BMI and the number of metabolic abnormalities (based on the Adult Treatment Panel-III). Metabolically healthy (MH) obesity was defined as BMI ≥30 kg/m2 in the presence of normoglycemia, normal blood pressure, and normal levels of fasting triglyceride and HDL-cholesterol levels (n = 631).

RESULTS

A total of 734 new cases of diabetes were diagnosed during 210,282 person-years of follow-up. The incidence rate of diabetes among participants with no metabolic risk factors was 1.15, 2.10, and 4.34 cases per 1,000 person-years among lean, overweight, and obese participants, respectively. In a multivariable model adjusted for age, region of origin, family history of diabetes, physical activity, fasting plasma glucose, triglyceride level, HDL-cholesterol, systolic blood pressure, and white blood cell count, a higher diabetes risk was observed among MH-overweight (hazard ratio [HR] 1.89 [95% CI 1.25-2.86]; P < 0.001) and MH-obese (HR 3.88 [95% CI 1.94-7.77]; P < 0.001) compared with MH-normal weight subjects. There was no interaction between BMI and the number of metabolic abnormalities at enrollment in predicting diabetes risk.

CONCLUSIONS

Healthy metabolic profile and the absence of diabetes risk factors do not protect young adults from incident diabetes associated with overweight and obesity.

Adolescent obesity and midlife cancer risk: a population-based cohort study of 2·3 million adolescents in Israel

BACKGROUND

Obesity has been established as a causal factor for several types of cancer, and adolescent obesity is increasing worldwide. We examined associations between measured body-mass index (BMI) at age 17 years and cancer incidence, and with mortality among those who developed cancer.

METHODS

In a nationwide, population-based cohort of adolescents, height and weight were measured at pre-recruitment mandatory medical examination during 1967-2010. BMI was classified according to US Center for Disease Control and Prevention percentiles. We applied Cox proportional hazard models to estimate the hazard ratios (HRs) and 95% CIs for incident cases of cancer using the 5th-49th BMI percentile group as a reference. The primary outcome was any cancer diagnosis between Jan 1, 1967, and Dec 31, 2012, as recorded in the Israeli National Cancer Registry. Participants with a diagnosis of cancer at baseline (before military recruitment assessment) were excluded from this analysis. The secondary outcome of this study was all-cause mortality among cohort members who had cancer, between Jan 1, 1967, and Dec 31, 2017.

FINDINGS

Of the 2 458 170 participants examined between Jan 1, 1967, and Dec 31, 2010, 160 040 were excluded. 2 298 130 participants of which 928 110 were women and 1 370 020 were men. During 29 542 735 person-years of follow-up in men, 26 353 incident cases of cancer were recorded and in 18 044 863 person-years of follow-up in women, 29 488 incident cases of cancer were recorded. Cancer incidence increased gradually across BMI percentiles. The adjusted HR was 1·26 (95% CI 1·18-1·35) among men with adolescent obesity. Among women, we found no association between obesity and overall cancer, driven by inverse associations of obesity with cervical and breast cancers. When these cancers were excluded, the adjusted HR for cancer was 1·27 (1·13-1·44) among women with adolescent obesity. In both sexes, high BMI (≥85th percentile) was associated with an increased cancer risk after 10 years. This association was accentuated in the late period of the cohort versus the early period of the cohort. BMI was positively associated with a higher risk of mortality. The projected population attributable risk for high BMI was 5·1% (4·2-6·1) for men and 5·7% (4·2-7·3) for women.

INTERPRETATION

The increasing prevalence of adolescent obesity and the possible association between adolescent BMI and cancer incidence might increase the future burden of obesity-related cancers. BMI among adolescents could constitute an important intervention target for cancer prevention.

FUNDING

None.

Associations of body mass index and body height with low back pain in 829,791 adolescents

Body mass index (BMI) (calculated as weight (kg)/height (m)²) and height are linked to the pathogenesis of low back pain, but evidence-based confirmation is lacking. We examined the prevalence of low back pain in adolescents and its association with BMI and height. Disability clauses (official military limitations related to a person's health status) indicating low back pain severity were divided according to symptoms of low back pain alone and symptoms of low back pain with objective corroborating findings. All 829,791 males and females undergoing mandatory premilitary recruitment examinations since 1998 were included. Logistic regression models assessed the relationships of BMI and height with low back pain. Prevalence of low back pain was 0.2% for both males and females with objective findings and 5.2% for males and 2.7% for females without objective findings. Higher BMI was significantly associated with low back pain in males (for overweight, odds ratio = 1.097, P < 0.001; for obese, odds ratio = 1.163, P < 0.001) and in females (for overweight, odds ratio = 1.174, P < 0.001; for obese, odds ratio = 1.211, P < 0.001). Height was associated with increased risk of low back pain in both genders. Odds ratios for low back pain in the tallest group compared with the shortest group were 1.438 (P < 0.001) for males and 1.224 (P < 0.001) for females. Low back pain with or without objective findings was associated with overweight and obesity as well as with height.

A large-scale study on epidemiology and risk factors for chronic ankle instability in young adults

Up to 40% of ankle sprains can result in chronic ankle instability (CAI). The prevalence of CAI and its association with body mass index (BMI) and height in the general young adult population has not been reported. The database records of young adults before recruitment into mandatory military service were studied. Information on the disability codes associated with CAI was retrieved. Logistic regression models were used to assess the association between the BMI and body height with various grades of CAI severity. The study cohort included 829,791 subjects (470,125 males and 359,666 females). The prevalence was 0.7% for mild CAI and 0.4% for severe instability in males and 0.3% and 0.4%, respectively, for females (p < .001). An increased BMI was associated with ankle instability in males (overweight, odds ratio [OR] 1.249, p < .001; obese, OR 1.418, p < .001) and females (overweight, OR 1.989 p < .001; obese, OR 2.754, p < .001). The body height was associated with an increased risk of CAI when the highest height quintile was compared with the lowest height quintile in both males (OR 2.443, p < .001) and females (OR 1.436, p < .001) for all levels of instability severity. The present study has shown a greater prevalence of CAI among males than females in a general healthy young adult population. CAI was associated with an increased BMI and greater body height for all grades of instability severity.

Mortality risk factors associated with familial Mediterranean fever among a cohort of 1.25 million adolescents

OBJECTIVE

There are limited data on long-term comorbidities and mortality among patients with familial Mediterranean fever (FMF). Our objective was to evaluate comorbidities and death rates among individuals with FMF.

METHODS

We studied a nationwide, population-based, retrospective cohort of 1225 individuals with FMF (59% men) in a database of 1 244 350 adolescents (16-20 years of age) medically evaluated for military service between 1973 and 1997. This cohort was linked with the national mortality, cancer and end-stage renal disease (ESRD) registries in Israel. Study outcomes were all-cause mortality, occurrence of ESRD and malignancy by the age of 50 years.

RESULTS

During 30 years of follow-up, death rates were 8.73/10(4) versus 4.32/10(4) person-years in the FMF and control groups, respectively (p=0.002). In a multivariable analysis adjusted for age, birth year, socio-economic status, education, ethnicity and body mass index, FMF was associated with increased mortality in men (HR=1.705 (95% CI 1.059 to 2.745), p=0.028) and women (HR=2.48 (1.032 to 5.992), p=0.042). Renal amyloidosis accounted for 35% and 60% of deaths in men and women, respectively. FMF was not associated with an increased incidence of cancer.

CONCLUSIONS

FMF is associated with increased all-cause mortality that is likely attributed to reduced colchicine compliance or responsiveness. Individuals with FMF do not have an increased incidence of cancer. These results support the awareness among medical community to decrease the higher than average mortality rate among participants with FMF.

White blood cell count and the risk for coronary artery disease in young adults

Background

The association between white blood cell (WBC) count and coronary artery disease (CAD) is unknown in young adults. Our objective was to assess the association between WBC count and its changes over time with CAD incidence in the Metabolic, Life-style and Nutrition Assessment in Young adults (MELANY) study, a cohort of Israeli army personnel.

Methods and Findings

29,120 apparently healthy young men (mean age; 31.2±5.5 years) with a normal baseline WBC count (3,000–12,000 cells/mm³) were followed during a mean follow up of 7.5±3.8 years for incidence of CAD. Participants were screened every 3–5 years using a stress test, and CAD was confirmed by coronary angiography. In a multivariate model adjusted for age, body mass index (BMI), LDL- and HDL-cholesterol, blood pressure, family history of CAD, physical activity, diabetes, triglycerides and smoking status, WBC levels (divided to quintiles) above 6,900 cells/mm³ (quintile 4) were associated with a 2.17-fold increase (95%CI = 1.18–3.97) in the risk for CAD as compared with men in quintile 1 (WBC≤5,400 cells/mm³). When modeled as a continuous variable, a WBC increment of 1000 cells/mm³ was associated with a 17.4% increase in CAD risk (HR 1.174; 95%CI = 1.067–1.290, p = 0.001). A decrease in the WBC level (within the normal range) during the follow-up period was associated with increased physical activity and decreased triglyceride levels as well as with reduced incidence of CAD.

Conclusions

WBC count is an independent risk factor for CAD in young adults at values well within the normal range. WBC count may assist in detecting subgroups of young men at either low or high risk for progression to CAD.

Cognitive function and the risk for diabetes among young men

OBJECTIVE

Diabetes is a risk factor for an accelerated rate of cognitive decline and dementia. However, the relationship between cognitive function and the subsequent development of diabetes is unclear.

RESEARCH DESIGN AND METHODS

We conducted a historical-prospective cohort study merging data collected at premilitary recruitment assessment with information collected at the Staff Periodic Examination Center of the Israeli Army Medical Corps. Included were men aged 25 years or older without a history of diabetes at the beginning of follow-up with available data regarding their general intelligence score (GIS), a comprehensive measure of cognitive function, at age 17 years.

RESULTS

Among 35,500 men followed for a median of 5.5 years, 770 new cases of diabetes were diagnosed. After adjustment for age, participants in the lowest GIS category had a 2.6-fold greater risk for developing diabetes compared with those in the highest GIS category. In multivariable analysis adjusted for age, BMI, fasting plasma glucose, sociogenetic variables, and lifestyle risk factors, those in the lowest GIS category had a twofold greater risk for incident diabetes when compared with the highest GIS category (hazard ratio 2.1 [95% CI 1.5-3.1]; P < 0.001). Additionally, participants in the lowest GIS category developed diabetes at a mean age of 39.5 ± 4.7 years and those in the highest GIS group at a mean age of 41.5 ± 5.1 years (P for comparison 0.042).

CONCLUSIONS

This study demonstrates that in addition to a potential causal link between diabetes and enhanced cognitive decline, lower cognitive function at late adolescence is independently associated with an elevated risk for future diabetes.

Flexible pes planus in adolescents: body mass index, body height, and gender--an epidemiological study

BACKGROUND

Most studies on the prevalence of flexible pes planus (FPP) have been conducted in pediatric populations and older adults. There is limited comparable information on these parameters for the adolescent age group. The purpose of this study was to report the prevalence of FPP and its association with body mass index (BMI), body height, and gender among healthy and fit adolescents.

METHODS

The data for this study were derived from a medical database containing records of 17-year-old males and females before their recruitment into mandatory military service. Information on the disability codes associated with FPP according to the Regulations of Medical Fitness Determination was retrieved. Logistic regression models were used to assess the association between BMI, body height, and gender to various grades of FPP severity.

RESULTS

The study cohort included 825 964 adolescents (467 412 males and 358 552 females). The prevalence was 12.4% for mild FPP and 3.8% for severe FPP among the males and 9.3% and 2.4%, respectively, for the females. An increased BMI was associated with FPP in both males (overweight: odds ratio [OR] 1.385, confidence interval [CI] 1.352-1.419, P < .001; obese: OR 1.765, CI 1.718-1.813, P < .001) and females (overweight: OR 1.408, CI 1.365-1.620, P < .001; obese: OR 1.549, CI 1.481-1.620, P < .001). Body height was associated with a decreased risk of FPP when the highest height quintile was compared with the lowest height quintile in both males (OR 0.782, CI 0.762-0.802, P < .001) and females (OR 0.730, CI 0.707-0.754, P < .001) for all FPP severity grades.

CONCLUSIONS

There was a greater prevalence of FPP among males compared with females in a general healthy adolescent age group. FPP was associated with increased BMI and shorter body height for all grades of FPP severity.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Hypertension in late adolescence and cardiovascular mortality in midlife: a cohort study of 2.3 million 16- to 19-year-old examinees

BACKGROUND

The effect of early hypertension on midlife cardiovascular (CV) mortality remains controversial. We assessed the association of established hypertension in late adolescence with subsequent CV mortality.

METHODS

Of 2,298,130 Israeli adolescents (60% males; age 17.4 ± 0.3 years) who underwent a compulsory medical examination prior to military service between 1967 and 2010, 8720 teenagers (0.4%) were formally diagnosed with persistent hypertension. Using Cox proportional hazards modeling, we compared the hypertensive group to the large normotensive group with regard to time to event analysis of midlife mortality due to cerebrovascular accidents (CVA), coronary heart disease (CHD), sudden death (SD) and their summation as cardiovascular disease (CVD).

RESULTS

During 45,729,521 person-years of follow-up, we identified 2918 CV deaths-2879 and 39 among the 2,289,410 normotensive and 8720 hypertensive adolescents, respectively. Hypertension at a young age was associated with a threefold elevation of stroke mortality compared to normotension when adjusted for sex, age at examination, birth year, country of origin, socioeconomic status, education, body mass index (BMI) and height [hazard ratio (HR) 3.12; 95% confidence interval (CI) 1.76-5.54; p < 0.001]. There was no significant association of hypertension with CHD mortality or SD. An increased risk for overall CVD mortality among hypertensive youngsters (HR 1.51; 95 % CI 1.10-2.07) was attenuated after adjusting for BMI and other covariates (HR 1.24; 95% CI 0.90-1.72).

CONCLUSIONS

Established hypertension at a young age was independently associated with elevated stroke mortality in midlife. This finding warrants confirmatory large-scale long-term follow-up studies to address the distant effects of adolescent hypertension.

Adolescent overweight and obesity and the risk for pancreatic cancer among men and women: a nationwide study of 1.79 million Israeli adolescents

BACKGROUND

There is growing concern regarding the impact of adolescent obesity on adult health. The objective of this study was to evaluate the association between body mass index (BMI) in late adolescence and the incidence of pancreatic cancer during adulthood.

METHODS

The authors analyzed a cohort of 1087,358 Israeli Jewish men and 707,212 Jewish women who underwent a compulsory physical examination between ages 16 and 19 years from 1967 to 2002. Pancreatic cancer incidence through December 31, 2012 was identified by linkage to the national cancer registry. Multivariable-adjusted Cox regression was used to estimate hazard ratios (HRs) for pancreatic cancer according to the US Centers for Disease Control and Prevention (CDC) BMI percentiles at baseline.

RESULTS

Over a median 23 year follow-up, 551 incident cases of pancreatic cancer cases occurred (423 men; 128 women). Compared with normal weight (5th to-<85th percentile), obesity (≥95th percentile) was associated with an increased risk of cancer among both men (HR, 3.67; 95% confidence interval [CI], 2.52-5.34) and women (HR, 4.07; 95% CI, 1.78-9.29). Among men, compared with low-normal BMI (≥5th to <25th percentile), high-normal BMI (≥75th to <85th percentile) and overweight (85th to 95th percentile) also were associated with a higher risk for cancer(high-normal BMI: HR, 1.49; 95% CI, 1.05-2.13; overweight: HR, 1.97; 95% CI, 1.39-2.80). The estimated population-attributable fraction because of overweight and obesity was 10.9% (95% CI, 6.1%-15.6%).

CONCLUSIONS

Men and women who were obese or overweight as adolescents are at an increased risk for subsequent pancreatic cancer.

Different effects of long-term exposures to SO2 and NO2 air pollutants on asthma severity in young adults

Numerous studies demonstrated that exposure to ambient air pollutants contributes to severity and frequency of asthma exacerbations. However, whether common air pollutants, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), exert differential effects on asthma occurrence and severity is unclear. The aim of this investigation was to determine whether exposure to NO2 and/or SO2 may initiate different long-term effects on prevalence and severity of asthma in young adults. Medical records of 137,040 males, 17 years old, who underwent standard premilitary service health examinations during 1999-2008 were examined. Air-pollution data for NO2 and SO2 were linked to the place of residence of each subject. The influence of specific air pollutants on asthma prevalence and severity was evaluated using bivariate logistic regression, controlling for individuals' sociodemographic attributes. For both ambient air pollutants, there was a significant dose-response effect on severity of asthma at ambient concentrations below the current National Ambient Air Quality Standards. However, in residential areas with high levels of SO2 (13.3-592.7µg/m(3)) and high levels of NO2 (27.2-43.2µg/m(3)) the risk of asthma occurrence was significantly higher than that in residential areas with high levels of NO2 (27.2-43.2 µg/m(3)) and intermediate levels (6.7-13.3 µg/m(3)) of SO2 pollution. The effects of exposure to SO2 and NO2 air pollutants on the respiratory airways system appear to differ, with possible implications regarding medical management, even in cases of exposure to mixtures of these pollutants.

Large population study shows that adolescents with celiac disease have an increased risk of multiple autoimmune and nonautoimmune comorbidities

AIM

Celiac disease (CD) is a systemic disorder that is associated with various autoimmune disorders and a higher prevalence of other diagnoses and complications. This large, cross-sectional, population-based study investigated the associations between CD and various medical conditions during late adolescence.

METHODS

We included 2 001 353 Jewish Israeli adolescents who underwent a general health examination at a median age of 17.1 (16.9-17.4) years from 1988 to 2015. Comprehensive data regarding medical status were available for 1 588 041 (79%) subjects. A definite diagnosis of CD was based on accepted criteria. Covariate data included demographic measures and data on associated medical conditions.

RESULTS

Overall, data on 7145 subjects with CD and 1 580 896 controls were analysed. Multivariate analyses showed that autoimmune diseases were significantly more common in subjects with CD, including insulin dependent diabetes, with an odds ratio (OR) of 5.5, inflammatory bowel diseases (OR = 3.8), arthritis (OR = 2.4), thyroid diseases (OR = 1.8) and psoriatic skin disorders (OR = 1.6). Further associations included asthma (OR = 1.5), bile stones (OR = 3.6), migraine (OR = 2.3), anaemia (OR = 1.7) and menstrual abnormalities (OR = 1.5). Long bone fractures and axial fractures were no more common in adolescents with CD than controls.

CONCLUSION

CD was already associated with multiple comorbidities by adolescence, and these were not limited to autoimmune disorders.

Adolescence BMI and trends in adulthood mortality: a study of 2.16 million adolescents

CONTEXT

The consequence of elevated body mass index (BMI) at adolescence on early adulthood mortality rate and on predicted life expectancy is unclear.

OBJECTIVE

The objective of the investigation was to study the relationship between BMI at adolescence and mortality rate as well as the mortality trend over the past 4 decades across the entire BMI range.

DESIGN AND SETTING

The study included a nationwide longitudinal cohort.

PARTICIPANTS

A total of 2 159 327 adolescents (59.1% males) born between 1950 and 1993, who were medically evaluated for compulsory military service in Israel, participated in the study.

INTERVENTIONS

Height and weight were measured at age 17 years, and BMI was stratified based on the Centers for Disease Control and Prevention-established percentiles for age and sex.

MAIN OUTCOME MEASURE

Incident cases of all-cause mortality before age 50 years were recorded. Cox-proportional hazard models were used to assess mortality rates and its trend overtime.

RESULTS

During 43 126 211 person-years of follow-up, 18 530 deaths were recorded. As compared with rates observed in the 25th to 50th BMI percentiles, all-cause mortality continuously increased across BMI range, reaching rates of 8.90/10(4) and 2.90/10(4) person-years for men and women with BMI greater than the 97th percentile, respectively. A multivariate analysis adjusted for age, socioeconomic status, education, and ethnicity demonstrated a significant increase in mortality at BMI greater than the 50th percentile (BMI > 20.55 kg/m(2)) for men and the 85th percentile or greater in women (BMI > 24.78 kg/m(2)). During the last 4 decades, a significant decrease in mortality rates was documented in normal-weight participants born between 1970 and 1980 vs those born between 1950 and 1960 (3.60/104 vs 4.99/10(4) person-years, P < .001). However, no improvement in the survival rate was observed among overweight and obese adolescents during the same time interval. Significant interaction between BMI and birth year was observed (P = .007).

CONCLUSIONS

BMI at adolescence, within the normal range, is associated with all-cause mortality in adulthood. Mortality rates among overweight and obese adolescents did not improve in the last 40 years, suggesting that preadulthood obesity may attenuate the progressive increase in life expectancy.