Hypermobility Among Adolescents and the Association With Spinal Deformities: A Large Cross-Sectional Study

INTRODUCTION

Adolescent idiopathic scoliosis and Scheuermann kyphosis are common spinal deformities (SD) among adolescents. The potential link between hypermobility and SD is a topic of debate. We aimed to investigate the prevalence of hypermobility and its association with SD.

METHODS

A cross-sectional analysis of records of 17-year-old subjects who were recruited into mandatory military service was conducted. Study population comprised 1,220,073 subjects. Prevalence rates were calculated for hypermobility and different categories of SD by severity, studying the strength of the association between hypermobility and SD.

RESULTS

Of 1,220,073 subjects, 0.0111% exhibited hypermobility. Spinal deformities were identified in 10.5% of subjects. Specifically, 7.9% had mild SD, 2.4% had moderate SD, and 0.1% had severe SD. The overall association between hypermobility and SD showed an odds ratio of 2.31 (P < 0.001). Subgroup analyses revealed ORs of 1.226 (P = 0.041) for mild deformities, 5.783 (P < 0.001) for moderate deformities, and 4.01 (P = 0.002) for severe deformities. The association was stronger for moderate and severe SD.

CONCLUSIONS

This study establishes a notable association between hypermobility and SD among adolescents. The findings highlight the importance of understanding this relationship, which could contribute to advancements in comprehending SD development. Additional research is warranted to expand upon these findings.

Stuttering in adolescence and the risk for dysglycemia in early adulthood

AIMS

To investigate the association between stuttering during adolescence and the onset of dysglycemia (prediabetes or type 2 diabetes) in early adulthood among men and women.

MATERIALS AND METHODS

This cohort study included Maccabi Health Services members assessed for mandatory military service at ages 16-19 during 1990-2019 and followed until 31 December 2020. Stuttering status was recorded in the baseline medical evaluation. Incident cases of dysglycemia were identified systematically using prediabetes and diabetes registries. Cox proportional hazard models were applied for men and women separately, adjusting for sociodemographics and medical status.

RESULTS

The study cohort comprised 866,304 individuals (55% men; 0.21% with stuttering) followed for a total of 12,696,250 person-years. During the study period, 7.6% (n = 36,603) of men and 9.0% (n = 34,723) of women were diagnosed with dysglycemia. The mean ages at diagnosis were 34 and 32 years for men and women, respectively. Women with stuttering exhibited the highest dysglycemia incidence rate (102.3 per 10,000 person-years) compared with the other groups (61.4, 69.0, and 51.9 per 10,000 person-years for women without stuttering, men with stuttering, and men without stuttering, respectively). For both men and women, those with stuttering showed an increased risk of being diagnosed with dysglycemia compared with those without (adjusted hazard ratios 1.18 [1.01-1.38] and 1.61 [1.15-2.26], respectively). The associations persisted in extensive sub-analyses.

CONCLUSIONS

Stuttering in adolescence is associated with a higher risk of dysglycemia in early adulthood for men and women. Screening and targeted prevention in this population, especially women, may be beneficial.

Adolescent Body Mass Index and Early Chronic Kidney Disease in Young Adulthood

Importance

Despite increasing obesity rates in adolescents, data regarding early kidney sequelae are lacking.

Objective

To assess the association between adolescent body mass index (BMI) and early chronic kidney disease (CKD) in young adulthood (<45 years of age).

Design, Setting, and Participants

This cohort study linked screening data of mandatory medical assessments of Israeli adolescents to data from a CKD registry of a national health care system. Adolescents who were aged 16 to 20 years; born since January 1, 1975; medically evaluated for mandatory military service through December 31, 2019; and insured by Maccabi Healthcare Services were assessed. Individuals with kidney pathology, albuminuria, hypertension, dysglycemia, or missing blood pressure or BMI data were excluded. Body mass index was calculated as weight in kilograms divided by height in meters squared and categorized by age- and sex-matched percentiles according to the US Centers for Disease Control and Prevention. Follow-up started at the time of medical evaluation or January 1, 2000 (whichever came last), and ended at early CKD onset, death, the last day insured, or August 23, 2020 (whichever came first). Data analysis was performed from December 19, 2021, to September 11, 2023.

Main Outcomes and Measures

Early CKD, defined as stage 1 to 2 CKD by moderately or severely increased albuminuria, with an estimated glomerular filtration rate of 60 mL/min/1.73 m2 or higher.

Results

Of 629 168 adolescents evaluated, 593 660 (mean [SD] age at study entry, 17.2 [0.5] years; 323 293 [54.5%] male, 270 367 [45.5%] female) were included in the analysis. During a mean (SD) follow-up of 13.4 (5.5) years for males and 13.4 (5.6) years for females, 1963 adolescents (0.3%) developed early CKD. Among males, the adjusted hazard ratios were 1.8 (95% CI, 1.5-2.2) for adolescents with high-normal BMI, 4.0 (95% CI, 3.3-5.0) for those with overweight, 6.7 (95% CI, 5.4-8.4) for those with mild obesity, and 9.4 (95% CI, 6.6-13.5) for those with severe obesity. Among females, the hazard ratios were 1.4 (95% CI, 1.2-1.6) for those with high-normal BMI, 2.3 (95% CI, 1.9-2.8) for those with overweight, 2.7 (95% CI, 2.1-3.6) for those with mild obesity, and 4.3 (95% CI, 2.8-6.5) for those with severe obesity. The results were similar when the cohort was limited to individuals who were seemingly healthy as adolescents, individuals surveyed up to 30 years of age, or those free of diabetes and hypertension at the end of the follow-up.

Conclusions and Relevance

In this cohort study, high BMI in late adolescence was associated with early CKD in young adulthood. The risk was also present in seemingly healthy individuals with high-normal BMI and before 30 years of age, and a greater risk was seen among those with severe obesity. These findings underscore the importance of mitigating adolescent obesity rates and managing risk factors for kidney disease in adolescents with high BMI.

Statistical Methods and Machine Learning Algorithms for Investigating Metabolic Syndrome in Temporomandibular Disorders: A Nationwide Study

The objective of this study was to analyze the associations between temporomandibular disorders (TMDs) and metabolic syndrome (MetS) components, consequences, and related conditions. This research analyzed data from the Dental, Oral, Medical Epidemiological (DOME) records-based study which integrated comprehensive socio-demographic, medical, and dental databases from a nationwide sample of dental attendees aged 18-50 years at military dental clinics for 1 year. Statistical and machine learning models were performed with TMDs as the dependent variable. The independent variables included age, sex, smoking, each of the MetS components, and consequences and related conditions, including hypertension, hyperlipidemia, diabetes, impaired glucose tolerance (IGT), obesity, cardiac disease, obstructive sleep apnea (OSA), nonalcoholic fatty liver disease (NAFLD), transient ischemic attack (TIA), stroke, deep venous thrombosis (DVT), and anemia. The study included 132,529 subjects, of which 1899 (1.43%) had been diagnosed with TMDs. The following parameters retained a statistically significant positive association with TMDs in the multivariable binary logistic regression analysis: female sex [OR = 2.65 (2.41-2.93)], anemia [OR = 1.69 (1.48-1.93)], and age [OR = 1.07 (1.06-1.08)]. Features importance generated by the XGBoost machine learning algorithm ranked the significance of the features with TMDs (the target variable) as follows: sex was ranked first followed by age (second), anemia (third), hypertension (fourth), and smoking (fifth). Metabolic morbidity and anemia should be included in the systemic evaluation of TMD patients.

Hypermobility spectrum disorders and irritable bowel syndrome: A nationwide study of 1.6 million adolescents

BACKGROUND AND AIM

The association between hypermobility spectrum disorders/hypermobile type Ehlers-Danlos syndrome (HDS/hEDS) and irritable bowel syndrome (IBS) is yet to be clarified. We aimed to assess this association in a national sample of adolescents.

METHODS

A population-based cross-sectional study included 1 627 345 Israeli adolescents (58% male; mean age 17 years) who were medically assessed before compulsory military service during 1998-2020. Diagnoses of HSD/hEDS and IBS were confirmed by board-certified specialists. The prevalence and odds ratios (ORs) for IBS in adolescents with and without HSD/hEDS were computed.

RESULTS

A total of 4686 adolescents (2553 male) with HSD/hEDS were identified, of whom 71 were diagnosed with IBS (prevalence = 1.5%). Of the 1 621 721 adolescents in the control group, 8751 were diagnosed with IBS (prevalence = 0.5%). Unadjusted logistic regression revealed a significant association between HSD/hEDS and IBS (OR = 2.16 [95% confidence interval, CI, 1.90-2.45]), which persisted in multivariable adjusted models (OR = 2.58 [95% CI, 2.02-3.24]), and in several sensitivity analyses. The association was evident in both male and female adolescents with ORs of 2.60 (95% CI, 1.87-3.49), and 2.46 (95% CI, 1.66-3.49), respectively. The association was accentuated in a sensitivity analysis accounting for other medical and psychiatric comorbidities.

CONCLUSIONS

We found a significant association between HSD/hEDS and IBS in both male and female adolescents. Clinical awareness of the association can promote early diagnosis of IBS and appropriate multidisciplinary treatment. Further research is required to identify the common pathological pathways of the conditions and to develop new IBS treatment strategies for people with HSD/hEDS.

Periodontitis and Metabolic Syndrome: Statistical and Machine Learning Analytics of a Nationwide Study

This study aimed to analyze the associations between periodontitis and metabolic syndrome (MetS) components and related conditions while controlling for sociodemographics, health behaviors, and caries levels among young and middle-aged adults. We analyzed data from the Dental, Oral, and Medical Epidemiological (DOME) record-based cross-sectional study that combines comprehensive sociodemographic, medical, and dental databases of a nationally representative sample of military personnel. The research consisted of 57,496 records of patients, and the prevalence of periodontitis was 9.79% (5630/57,496). The following parameters retained a significant positive association with subsequent periodontitis multivariate analysis (from the highest to the lowest OR (odds ratio)): brushing teeth (OR = 2.985 (2.739-3.257)), obstructive sleep apnea (OSA) (OR = 2.188 (1.545-3.105)), cariogenic diet consumption (OR = 1.652 (1.536-1.776)), non-alcoholic fatty liver disease (NAFLD) (OR = 1.483 (1.171-1.879)), smoking (OR = 1.176 (1.047-1.322)), and age (OR = 1.040 (1.035-1.046)). The following parameters retained a significant negative association (protective effect) with periodontitis in the multivariate analysis (from the highest to the lowest OR): the mean number of decayed teeth (OR = 0.980 (0.970-0.991)); North America as the birth country compared to native Israelis (OR = 0.775 (0.608-0.988)); urban non-Jewish (OR = 0.442 (0.280-0.698)); and urban Jewish (OR = 0.395 (0.251-0.620)) compared to the rural locality of residence. Feature importance analysis using the eXtreme Gradient Boosting (XGBoost) machine learning algorithm with periodontitis as the target variable ranked obesity, OSA, and NAFLD as the most important systemic conditions in the model. We identified a profile of the "patient vulnerable to periodontitis" characterized by older age, rural residency, smoking, brushing teeth, cariogenic diet, comorbidities of obesity, OSA and NAFLD, and fewer untreated decayed teeth. North American-born individuals had a lower prevalence of periodontitis than native Israelis. This study emphasizes the holistic view of the MetS cluster and explores less-investigated MetS-related conditions in the context of periodontitis. A comprehensive assessment of disease risk factors is crucial to target high-risk populations for periodontitis and MetS.

Body mass index and migraine in adolescence: A nationwide study

BACKGROUND

The association between body mass index (BMI) and migraine in adults has been well established. However, studies in children and adolescents are inconclusive. We aimed to study the association between BMI and migraine using a national dataset that comprises the electronic medical records of more than two million adolescents.

METHODS

This study included all Israeli adolescents (57.7% males, 42.3% females; mean age 17 years) who were medically assessed before mandatory military service during 1990-2020. As part of the pre-recruitment medical assessment, all the adolescents were screened for migraine and their height and weight were measured. Diagnoses of migraine were confirmed by board-certified neurologists. Prevalences and odds ratios (ORs) for migraine were computed across BMI subgroups. Spline models were applied.

RESULTS

A total of 2,094,862 adolescents were included, of whom 57,385 (2.8%) had active migraine. Among males, the adjusted ORs for migraine were 1.11 (95% confidence interval, 1.06-1.16), 1.13 (1.08-1.17), and 1.24 (1.19-1.30), for the underweight, overweight, and obesity subgroups, respectively, compared to the reference group of low-normal BMI (5th-49th percentile). Among females, the respective adjusted ORs were 1.12 (1.05-1.19), 1.23 (1.19-1.28), and 1.38 (1.31-1.46). Results persisted in sensitivity analyses accounting for other medical and psychiatric comorbidities and parental history of migraine. Spline models demonstrated a J-shaped relation between BMI and migraine.

CONCLUSIONS

Both adolescent obesity and underweight were associated with migraine in a sex-dependent manner. This association peaked in female adolescents with overweight and obesity.

Association Between Body Mass Index and Nonspecific Recurrent Low Back Pain in Over 600,000 Healthy Young Adults

An association between body mass index (BMI; weight (kg)/height (m)2) and low back pain (LBP) has long been debated, but inconsistent measurements of BMI and varying definitions of LBP have produced conflicting findings. We explored this association using measured BMI and physician documentation of recurrent LBP among healthy young adults. Data were extracted from the Israel Defense Forces electronic medical record system. All Israeli citizens with compulsory military service during January 2008-March 2019 were included (n = 705,840). Exclusion criteria were spine deformities, disc pathologies, spinal surgeries, arthropathies, connective tissue diseases, pain syndromes, low bone density disorders, cancers, and psychiatric illnesses. LBP was defined as electronic medical record system documentation of 1) 2 medical visits at least 6 weeks apart with a diagnosis of LBP or "LBP with radiation" or 2) 1 medical visit resulting in referral to an orthopedic surgeon. Logistic regression models were used to explore the association between BMI category and LBP; 619,969 (87.8%) individuals (mean age = 18.9 (standard deviation, 0.97) years; 56.9% male) were included. LBP prevalence was 9.2% (n = 56,918) and higher among males (9.7%) than females (8.5%). Overweight (odds ratio = 1.123, 95% confidence interval: 1.096, 1.151) and obesity (odds ratio = 1.137, 95% confidence interval: 1.096, 1.179) were associated with LBP. The association remained significant after accounting for various sociodemographic factors. Maintaining a healthy BMI may aid in the prevention of LBP in young adults.

Occupational Exposure to Nonionizing Radiation and Risk for Malignancy in Young Adults

INTRODUCTION

Nonionizing radiation (NIR) is considered "possibly carcinogenic to humans," and therefore, exposure of young military personnel raises concerns regarding increased risk for cancer. The aim of our study was to compare the cancer incidence in exposed and nonexposed populations in order to gain better understanding of their risk.

MATERIALS AND METHODS

A longitudinal retrospective cohort study, between 2009 and 2018, was conducted. Israel Defense Forces (IDF) aerial defense units service members, with NIR exposure (range of 2-300 GHz, below the International Commission of Non-Ionizing Radiation Protection guidelines), were compared with a similar sociodemographic group of service members without NIR exposure. Both groups were followed for cancer incidence (all-cause and specific malignancies). Kaplan-Meier analysis of cancer-free survival and univariate and multivariable logistic regressions for possible confounders and risk factors were performed. This analysis was repeated on a matched 1:1 control group.

RESULTS

Exposure and comparison groups included 3,825 and 11,049 individuals, respectively. Forty-one cases diagnosed with cancer were identified during the follow-up time (mean 4.8 [±2.7] years), 13 (0.34%) of which were reported in the exposure group, and 28 (0.25%) were reported in the comparison group. The odds ratio (OR) for cancer incidence in the exposure vs. control groups was 1.34 (95%CI, 0.70-2.60), P-value = 0.3807. The results remained unchanged after adjustment for sex, age at enrollment, service length, socioeconomic status, and military occupation (adjOR = 1.38 [95%CI, 0.67-2.82], P = 0.3818).

CONCLUSIONS

Our study did not find an increased short-term risk for cancer in young adults exposed to NIR radiation as compared with unexposed young adults.

Adolescent BMI and Cognitive Performance: A Nationwide Study of 2.48 Million Israeli Adolescents

OBJECTIVE

The increased incidence of adolescent obesity over recent decades may be associated with lower cognitive performance than the expected potential. Thus, we aimed to assess the association between adolescent body mass index (BMI) and cognitive function.

DESIGN

A nationwide, cross-sectional, population-based study including all Israeli-born adolescents, 1,459,522 males and 1,027,953 females aged 16 to 20 years old, who were evaluated for military service during 1967-2018.

METHODS

Weight and height were measured to calculate BMI. Cognitive performance was assessed by a validated Intelligence-Quotient-equivalent test and was standardized to the year- and sex-Z-score. For 445,385 persons, parental cognitive scores could be identified. Multinomial logistic regression models were applied.

RESULTS

Among male adolescents with severe obesity, 29.4% achieved a cognitive score below the 25th percentile, compared to 17.7% among their normal-weight (50th-84th percentile) counterparts. A largely J-shaped relation was observed between BMI and the odds ratio (OR) for a low cognitive score among male adolescents: underweight, 1.45 (1.43-1.48); overweight, 1.13 (1.12-1.15); mild obesity, 1.36 (1.33-1.39); and severe obesity, 1.58 (1.52-1.64). Similar findings were observed in females. For both sexes, point estimates were overall consistent in models adjusted for sociodemographic confounders, coexisting morbidities and parental cognitive scores. Examinees with abnormal BMI had higher ORs for lower-than-expected cognitive score, based on their parents' data as adolescents, in a manner that depends on obesity severity.

CONCLUSION

Abnormal BMI, and especially obesity, is associated with increased odds for a lower cognitive performance, and the inability to fully achieve cognitive potential, regardless of sociodemographic background.

Hypermobility spectrum disorders and active migraine in Israeli adolescents: A nationwide study

OBJECTIVE

To assess the association between hypermobility spectrum disorders/hypermobile type Ehlers Danlos Syndrome (HSD/hEDS) and migraine in a national sample of adolescents in Israel.

BACKGROUND

The association between HSD/hEDS and migraine is unclear, even more so in pediatric populations.

METHODS

This population-based, cross-sectional study included 1,627,345 Israeli adolescents (945,519/1,626,407 [58%] males; mean age 17 ± 0.5 years) who were medically assessed before mandatory military service during 1998-2020. Diagnoses of migraine with at least one attack per month (active migraine) and HSD/hEDS were confirmed by certified specialists. The prevalences of active migraine in adolescents with and without HSD/hEDS were computed and the association between HSD/hEDS and active migraine was examined.

RESULTS

Active migraine was significantly more prevalent in adolescents with HSD/hEDS (307/4686 [6.5%]) compared to those without HSD/hEDS (51,931/1,621,721 [3.2%]) (OR = 2.16, 95% CI 1.90-2.45). The association between HSD/hEDS and active migraine persisted in a multivariable analysis (OR = 2.08, 95% CI 1.85-2.34) and in several sensitivity analyses.

CONCLUSIONS

We found a significant association between HSD/hEDS and active migraine in both male and female adolescents. Clinical awareness of the association can promote early diagnosis and treatment of migraine. Further research is required to identify appropriate pharmacologic and nonpharmacologic migraine treatment strategies for individuals with HSD/hEDS.

COVID-19 vaccination - Does it affect sick leave in military personnel?

OBJECTIVE

Sick leave is a major negative economic effect of the COVID-19 pandemic. In April 2021, the Integrated Benefits Institute reported that employers spent a total of US $50.5 billion for workers absent due to the COVID-19 pandemic. While vaccination programs lowered the number of severe illness and hospitalizations worldwide, the number of side effects following vaccination against COVID-19 were high. The present study aimed to evaluate the effect of vaccination on the probability of taking sick leave in the week following vaccination.

SUBJECTS AND METHODS

The study population was comprised of all personnel serving in the Israel Defense Forces (IDF) between October 7, 2020, and October 3, 2021, (a total of 52 weeks) who were vaccinated with at least one dose of the BNT162b2 vaccine. Data on Israel Defense Forces (IDF) personnel sick leaves were retrieved and the probability of a "post-vaccination week sick leave" and a "regular (not post-vaccination week) sick leave" were analyzed. An additional analysis was performed to determine whether winter-related diseases or the sex of the personnel affected the probability of taking sick leave.

RESULTS

The probability of taking sick leave in a post-vaccination week was significantly higher than the probability of taking sick leave in a regular week (8.45% vs. 4.3%, respectively, p < 0.01). The increased probability remained unchanged after analysis of sex-related and winter disease-related variables.

CONCLUSIONS

Given the major effect of vaccination against COVID-19 by BNT162b2 vaccine on the probability of taking sick leave, when medically feasible, the timing of the vaccination should be considered by medical, military, and industrial authorities with the intent to minimize the effect on overall national economy and safety.

Is There an Association between BMI, Height, and Gender and Long-Bone Fractures during Childhood and Adolescence? A Large Cross-Sectional Population Study of 911,206 Subjects

INTRODUCTION

Traumatic long-bone fractures (TLFs) among children and adolescents are relatively common, with morbidity and economic consequences. Obesity has become a significant global concern. Studies have found an association between TLFs and BMI in the past but not in a large cross-sectional population study. Our study objective was to measure the incidence of TLFs in the 17-year-old general population and evaluate its association with BMI, body height, and gender.

METHODS

Data from a medical database containing all 17-year-old candidates' records before recruitment into mandatory military service were retrieved as BMI, height, gender, and history of TLFs. Logistic regression models assessed the association between BMI and height to TLFs.

RESULTS

The records of 911,206 subjects (515,339 males) were reviewed. In total, 9.65% had a history of TLFs (12.25% and 6.25% for males/females, respectively). Higher BMI was associated with TLF, with a linear trend in the odds ratio (OR) for having TLFs. The strongest association was found between obese females and TLFs (OR = 1.364, p < 0.0001). Height was an independent factor positively associated with TLFs. The OR for a TLF in the highest height quintile was 1.238 (p < 0.001) for males and 1.411 (p < 0.001) for females compared to the lowest quintile. Although TLFs were more common in males, the OR for TLFs was more prominent in females.

CONCLUSIONS

There is an association between BMI, body height, and TLFs in healthy adolescents. TLFs are more common in males, but the strongest association between overweight and obesity is evident in females.

Adolescent Hypertension Is Associated With Stroke in Young Adulthood: A Nationwide Cohort of 1.9 Million Adolescents

BACKGROUND

Adult hypertension is a well-established risk factor for stroke in young adults (aged <55 years), and the effects are even more deleterious than at an older age. However, data are limited regarding the association between adolescent hypertension and the risk of stroke in young adulthood.

METHODS

A nationwide, retrospective cohort study of adolescents (aged 16-19 years) who were medically evaluated before compulsory military service in Israel during 1985 to 2013. For each candidate for service, hypertension was designated after constructed screening, and the diagnosis was confirmed through a comprehensive workup process. The primary outcome was ischemic and hemorrhagic stroke incidence as registered at the national stroke registry. Cox proportional-hazards models were used. We conducted sensitivity analyses by excluding people with a diabetes diagnosis at adolescence or a new diabetes diagnosis during the follow-up period, analysis of adolescents with overweight, and adolescents with baseline unimpaired health status.

RESULTS

The final sample included 1 900 384 adolescents (58% men; median age, 17.3 years). In total, 1474 (0.08%) incidences of stroke (1236 [84%] ischemic) were recorded, at a median age of 43 (interquartile range, 38-47) years. Of these, 18 (0.35%) occurred among the 5221 people with a history of adolescent hypertension. The latter population had a hazard ratio of 2.4 (95% CI, 1.5-3.9) for incident stroke after adjustment for body mass index and baseline sociodemographic factors. Further adjustment for diabetes status yielded a hazard ratio of 2.1 (1.3-3.5). We found similar results when the outcome was ischemic stroke with a hazard ratio of 2.0 (1.2-3.5). Sensitivity analyses for overall stroke, and ischemic stroke only, yielded consistent findings.

CONCLUSIONS

Adolescent hypertension is associated with an increased risk of stroke, particularly ischemic stroke, in young adulthood.

Familial clustering of psychiatric disorders and low IQ

BACKGROUND

Although the ICD and DSM differentiate between different psychiatric disorders, these often share symptoms, risk factors, and treatments. This was a population-based, case-control, sibling study examining familial clustering of all psychiatric disorders and low IQ, using data from the Israel Draft-Board Registry on all Jewish adolescents assessed between 1998 and 2014.

METHODS

We identified all cases with autism spectrum disorder (ASD, N = 2128), severe intellectual disability (ID, N = 9572), attention-deficit hyperactive disorder (ADHD) (N = 3272), psychotic (N = 7902), mood (N = 9704), anxiety (N = 10 606), personality (N = 24 816), or substance/alcohol abuse (N = 791) disorders, and low IQ (⩾2 SDs below the population mean, N = 31 186). Non-CNS control disorders were adolescents with Type-1 diabetes (N = 2427), hernia (N = 29 558) or hematological malignancies (N = 931). Each case was matched with 10 age-matched controls selected at random from the Draft-Board Registry, with replacement, and for each case and matched controls, we ascertained all full siblings. The main outcome measure was the relative recurrence risk (RRR) of the sibling of a case having the same (within-disorder RRR) or a different (across-disorder RRR) disorder.

RESULTS

Within-disorder RRRs were increased for all diagnostic categories, ranging from 11.53 [95% confidence interval (CI): 9.23-14.40] for ASD to 2.93 (95% CI: 2.80-3.07) for personality disorders. The median across-disorder RRR between any pair of psychiatric disorders was 2.16 (95% CI: 1.45-2.43); the median RRR between low IQ and any psychiatric disorder was 1.37 (95% CI: 0.93-1.98). There was no consistent increase in across-disorder RRRs between the non-CNS disorders and psychiatric disorders and/or low IQ.

CONCLUSION

These large population-based study findings suggest shared etiologies among most psychiatric disorders, and low IQ.

Glucose intolerance in pregnancy and risk of early-onset type 2 diabetes: a population-based cohort study

BACKGROUND

The risk of type 2 diabetes among women with glucose intolerance during pregnancy that does not meet gestational diabetes criteria requires further investigation. We aimed to explore the associations between various degrees of gestational glucose intolerance and the risk of type 2 diabetes in young adulthood.

METHODS

For this population-based cohort study, the national Israeli conscription database was linked to Maccabi Healthcare Services (MHS), the second-largest state-mandated health provider in Israel. We included 177 241 women who underwent a pre-recruitment evaluation at adolescence (age 16-20 years), 1 year before mandatory military service, and later underwent, from Jan 1, 2001, to Dec 31, 2019, two-step gestational diabetes screening with a 50 g glucose challenge test (GCT) based on a threshold of 140 mg/dL (7·8 mmol/L), followed as needed by a 100 g oral glucose tolerance test (OGTT). Abnormal OGTT values were defined according to the Carpenter-Coustan thresholds: 95 mg/dL (5·3 mmol/L) or higher in the fasting state; 180 mg/dL (10·0 mmol/L) or higher at 1 h; 155 mg/dL (8·6 mmol/L) or higher at 2 h; and 140 mg/dL (7·8 mmol/L) or higher at 3 h. The primary outcome was incident type 2 diabetes in the MHS diabetes registry. Cox proportional hazards models were applied to estimate adjusted hazard ratios (HRs) with 95% CIs for incident type 2 diabetes.

FINDINGS

During a cumulative follow-up of 1 882 647 person-years, and with a median follow-up of 10·8 (IQR 5·2-16·4) years, 1262 women were diagnosed with type 2 diabetes. Crude incidence rates of type 2 diabetes were 2·6 (95% CI 2·4-2·9) per 10 000 person-years in women with gestational normoglycaemia, 8·9 (7·4-10·6) per 10 000 person-years in women with an abnormal GCT and normal OGTT, 26·1 (22·4-30·1) per 10 000 person-years in women with one abnormal OGTT value (in the fasting state or 1 h, 2 h, or 3 h post-challenge), and 71·9 (66·0-78·3) per 10 000 person-years in women with gestational diabetes. After adjustment for sociodemographic characteristics, adolescent BMI, and age at gestational screening, the risk of type 2 diabetes was higher, compared to the gestational normoglycaemia group, in women with an abnormal GCT and normal OGTT (adjusted hazard ratio [HR] 3·39 [95% CI 2·77-4·16]; p<0·0001), in women with one abnormal OGTT value (9·11 [7·64-10·86]; p<0·0001), and in women with gestational diabetes (24·84 [21·78-28·34]; p<0·0001). The risk of type 2 diabetes was modestly increased in women with isolated elevated fasting glucose (adjusted HR 11·81 [95% CI 8·58-16·25]; p<0·0001), and in women with gestational diabetes and an abnormal fasting glucose (38·02 [32·41-44·61]; p<0·0001).

INTERPRETATION

Gestational glucose intolerance, including conditions not meeting gestational diabetes criteria of the two-step strategy, confers a high risk of type 2 diabetes in young adulthood. These conditions should be recognised as risk factors for type 2 diabetes, especially among women with abnormal fasting glucose concentrations during pregnancy.

FUNDING

None.

Predictors of combat training attrition in Israel Defense Forces soldiers

BACKGROUND

Attrition from combat service carries significant organizational and personal ramifications, but predicting factors associated with attrition remains challenging.

AIMS

To evaluate medical and psychosocial factors associated with attrition from basic combat training (BCT) in the Israel Defense Forces (IDF). In addition, we identify subsets of the recruit population which exhibit certain trends in terms of medical corresponding with a high risk of attrition.

METHODS

A cross-sectional study of IDF combat trainees undergoing infantry BCT between 2012 and 2017. Data were collected from the soldiers' electronic medical and administrative records. We used multivariable logistic regression and the SAS® decision-tree tool to analyse key predictive factors for attrition.

RESULTS

A total of 46 472 soldiers enlisted to BCT during the research period. The mean body mass index (BMI) was 21.8 (SD 3.54). The overall attrition rate was 10%. The following factors were associated with attrition from BCT: ethnicity (P < 0.01), BMI (P < 0.01), pre-enlisting motivation score (P < 0.01) and the number of mental health officer visits (P < 0.01). Using a decision-tree model, we found a high attrition rate among soldiers who had >5.2 to primary care physician visits (11% attrition rate versus 3%) or more than 11 sick leave days (59% versus 19%).

CONCLUSIONS

This study sheds light on unique measures relating to attrition. Attrition is associated with several demographic and psychosocial factors. Early prediction of motivation and monitoring of healthcare utilization may enable early identification and focused interventions targeting soldiers at high risk for attrition. These findings need to be further translated into actionable directives and further investigations.

Being overweight and born in the spring are associated with an increased risk for rhinitis

AIM

To explore the relationship between the season of birth and the prevalence of recurrent or chronic rhinitis (rhinitis).

METHODS

The medical records of consecutive 17-year-old conscripts to the Israeli army were reviewed. We compared the prevalence of rhinitis between children born during different seasons. Multivariate analysis was performed with additional variables.

RESULTS

The prevalence of rhinitis among the 1.1 million recruits was 7.1% in males and 5.3% in females. The association between birth season and the prevalence of rhinitis was highly significant (p < 0.001 for both genders). Spring was the birth season with the highest prevalence of rhinitis (7.4% in males and 5.5% in females). Males born in the winter and females born in the autumn had the lowest prevalence of rhinitis (6.7%, and 5.2% respectively). There was an increased odds ratio for rhinitis among those with a body mass index above 25, higher cognitive score and maternal birth country out of Israel or Africa.

CONCLUSIONS

There was an increased risk of rhinitis among young Israeli adults who were born in the spring, were overweight and had a higher cognitive-score. Family planning to avoid a spring birth and preventing overweight may reduce the risk of chronic rhinitis.

RF28 | PSUN302 Obesity at Late Adolescence and Incident Type 1 Diabetes in Young Adulthood

Aims

Studies in children reported an association between increased body mass index (BMI) and risk for developing type 1 diabetes (T1D), but evidence in late adolescence is limited. We recently investigated the association between adolescent BMI and type 2 diabetes in young adulthood (Diabetes Care 2020, 43(7): 1487-95) and here we studied on the same cohort the association between late adolescent BMI and incident T1D.

Methods

All Israeli adolescents, ages 16-19, undergoing medical evaluation in preparation for mandatory military conscription between January 1996 and December 2016 were included for analysis unless they had a history of dysglycemia (n=1,462,362; 40% women). Data were linked to information about adult onset of T1D in the Israeli National Diabetes Registry. Weight and height were measured at study entry and BMI was computed and transformed to age- and sex-adjusted BMI percentiles according to US Center for Diseases Control. The definition of T1D was determined based on anti-diabetic drugs and was confirmed for a subpopulation of the cohort to which islet autoantibodies data were available. Cox proportional models were applied, with BMI analyzed both as a categorical and continuous variable.

Results

There were 777 incident cases of T1D during 15,810,751 person-years (mean age at diagnosis 25.2±3.9 years). The median follow-up period was 11.2 years (IQR 5.8-16.3), with follow-up length shorter for individuals with a higher BMI. The crude diabetes rate showed a consistent graded increase across BMI groups from underweight to obesity; 3.6 to 8.4 cases per 100,000 person-years, respectively.

In a multivariable model adjusted for age, sex and socio-demographic variables, the hazard ratios (HRs) for T1D were 1.05 (95% CI 0.87-1.27) for the 50th–74th BMI percentiles, 1.41 (1.11–1.78) for the 75th–84th BMI percentiles, 1.54 (1.23–1.94) for adolescents with overweight (85th–94th percentiles), and 2.05 (1.58–2.66) for adolescents with obesity (BMI≥95th percentile)(reference group, 5th-49th BMI percentile group). One increment in BMI standard deviation was associated with 25% greater risk for incidence of T1D (HR=1.25, 95%CI 1.17-1.32). when the presence of one or multiple (≥2) islet antibodies was added as a criterion for T1D definition, the HRs among those with adolescent obesity were 2.90 (1.80-4.68) and 3.14 (1.68-5.88) respectively. Results were marginally affected by level of adjustment for sociodemographic background, were similar when analysis was stratified by sex, and also persisted when the study population was limited to adolescents with unimpaired health in order to mitigate confounding by coexisting illness.

The fraction of type 1 diabetes attributed to adolescent overweight and obesity (Population attributable risk%; PAR%) was 10.1% (95%CI 6.3%-14.2%).

Conclusions

Adolescent overweight and obesity in apparently healthy adolescents were associated with increased risk for incident type 1 diabetes in early adulthood.

Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Monday, June 13, 2022 1:24 p.m. - 1:30 p.m.

Varicocele in adolescence and testicular cancer in young adulthood

BACKGROUND

Elevated intrascrotal temperature has been suggested as a risk factor for testicular cancer, which is the most common neoplasm among young men. Varicocele was linked to increased intrascrotal temperature, but whether it is associated with testicular cancer is unclear.

OBJECTIVE

To explore the possible association between varicocele at adolescence and the incidence of testicular cancer at adulthood.

DESIGN, SETTING AND PARTICIPANTS

This nationwide, population-based, historical cohort study includes 1,521,661 Israeli male adolecents (mean age 17.5 ± 0.4 years), who were screened for varicocele during the years 1967-2012, as part of their medical assessment prior to compulsory military service. The mean follow-up was 18± 4.2 years.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The diagnosis of testicular cancer was ascertained from linkage of records to the the Israeli National Cancer Registry. Survival analysis was applied.

RESULTS

In total, 53,210 adolescents were diagnosed with varicocele stage 2 and 3 prior to military service. Of 1,988 (0.13% of the total cohort) men who were diagnosed with testicular cancer during follow up, 54 (0.1%) had varicocele prior to military service while 1934(99.9%) did not, p = 0.213. The age at cancer diagnosis and the distribution of seminomas vs. non-seminomas did not differ significantly between those with and without varicocele in adolescence. In a multivariable analysis controlling for sociodemographic factors, varicocele was not associated with testicular cancer, odds ratio = 0.816 (CI 0.615-1.083).

CONCLUSIONS

Varicocele in adolecents was not found to be associated with testicular cancer in young adults.

PATIENT SUMMARY

In light of the theoretical association between varicocele and testicular cancer, we conducted this large population study. We found no association between varicocele in young adoulthoot and testicular cancer later in life. This article is protected by copyright. All rights reserved.

Obesity in late adolescence and incident type 1 diabetes in young adulthood

AIMS/HYPOTHESIS

Studies in children have reported an association between increased BMI and risk for developing type 1 diabetes, but evidence in late adolescence is limited. We studied the association between BMI in late adolescence and incident type 1 diabetes in young adulthood.

METHODS

All Israeli adolescents, ages 16-19 years, undergoing medical evaluation in preparation for mandatory military conscription between January 1996 and December 2016 were included for analysis unless they had a history of dysglycaemia. Data were linked with information about adult onset of type 1 diabetes in the Israeli National Diabetes Registry. Weight and height were measured at study entry. Cox proportional models were applied, with BMI being analysed both as a categorical and as a continuous variable.

RESULTS

There were 777 incident cases of type 1 diabetes during 15,819,750 person-years (mean age at diagnosis 25.2±3.9 years). BMI was associated with incident type 1 diabetes. In a multivariable model adjusted for age, sex and sociodemographic variables, the HRs for type 1 diabetes were 1.05 (95% CI 0.87, 1.27) for the 50th-74th BMI percentiles, 1.41 (95% CI 1.11, 1.78) for the 75th-84th BMI percentiles, 1.54 (95% CI 1.23, 1.94) for adolescents who were overweight (85th-94th percentiles), and 2.05 (95% CI 1.58, 2.66) for adolescents with obesity (≥95th percentile) (reference group: 5th-49th BMI percentiles). One increment in BMI SD was associated with a 25% greater risk for incidence of type 1 diabetes (HR 1.25, 95% CI 1.17, 1.32).

CONCLUSIONS

Excessively high BMI in otherwise healthy adolescents is associated with increased risk for incident type 1 diabetes in early adulthood.

Symptomatic Joint Hypermobility Is Associated with Low Back Pain: A National Adolescents Cohort Study

Background: Low back pain (LBP) is a widespread medical complaint affecting many people worldwide and costing billions. Studies suggest a link between LBP and joint hypermobility. This study aimed to examine the association between symptomatic joint hypermobility (SJH), LBP, and gender. Methods: Data were obtained from a medical database containing 17-year-old candidates’ records before recruitment into mandatory military service. According to the Regulations of Medical Fitness Determination, information on disability codes associated with LBP and SJH was retrieved. Results: According to this national survey, the prevalence of SJH is 0.11% (1355 cases out of 1,220,073 subjects). LBP was identified in 3.7% of the cohort (44,755 subjects). Subjects were further subdivided into LBP without objective findings (LBPWF) (3.5%) and LBP with objective findings (LBPOF) (0.2%). The association between SJH and LBP was examined: the Odds Ratio (OR) was 2.912 (p < 0.0001). The odds rations for LBPWF and LBPOF were further calculated to be 2.914 (p < 0.000) and 2.876 (p < 0.000), respectively. Subjects with SJH were almost three times more prone to LBPWF and LBPOF. Conclusion: SJH is strongly associated with LBP in young adults. Further pathophysiological research is needed.

Myopia and BMI: a nationwide study of 1.3 million adolescents

OBJECTIVE

This study analyzed the association between adolescent BMI and myopia severity.

METHODS

This cross-sectional study comprised 1,359,153 adolescents who were medically examined before mandatory military service. Mild-to-moderate and high myopia were defined based on right-eye refractive data. BMI was categorized based on the US age- and sex-matched percentiles. Logistic regression models were applied separately for women and men to estimate odds ratios (ORs) for myopia per BMI category.

RESULTS

A total of 318,712 adolescents had mild-to-moderate myopia and 23,569 had high myopia. Compared with low-normal BMI (reference group), adjusted ORs for mild-to-moderate and high myopia increased with increasing BMI status, reaching 1.39 (95% CI: 1.23-1.57) and 1.73 (95% CI: 1.19-2.51) for men with severe obesity, respectively, and 1.19 (95% CI: 1.12-1.27) and 1.38 (95% CI: 1.14-1.65) for women with mild obesity, respectively. ORs for mild-to-moderate and high myopia were also higher in men with underweight (OR = 1.20; 95% CI: 1.18-1.23 and OR = 1.39; 95% CI: 1.30-1.47) and women with underweight (OR = 1.06; 95% CI: 1.03-1.09 and OR = 1.12; 95% CI: 1.04-1.22). The overall size effect was greater for men than women (p_interaction  < 0.001), in whom the group with severe obesity did not reach statistical significance.

CONCLUSIONS

BMI was associated with myopia in a J-shaped pattern, with the size effect being greater for adolescent men than women. This study indicates that both low BMI and high BMI are associated with mild-to-moderate and severe myopia.

Glucose Intolerance in Pregnancy and Offspring Obesity in Late Adolescence

OBJECTIVE

Gestational hyperglycemia is associated with deleterious neonatal outcomes, but long-term risks for offspring obesity are less clear. We estimated the odds for offspring adolescent overweight and obesity among mothers with gestational glucose intolerance.

RESEARCH DESIGN AND METHODS

In a mother-offspring historical cohort, the Israel military conscription data set was linked to a large health maintenance organization. Included were women who were evaluated at adolescence and underwent two-step gestational diabetes screening (mean age, 31 years) with a 50-g glucose challenge test (GCT), followed by a 100-g oral glucose tolerance test (OGTT) if the result was abnormal. Glucose tolerance categories included gestational normoglycemia, abnormal GCT with normal OGTT, impaired glucose tolerance (IGT; one abnormal OGTT value), and gestational diabetes. The primary outcome was offspring overweight/obesity (BMI ≥85th percentile) at adolescence, measured prior to military conscription. Logistic regression models were applied.

RESULTS

Of 33,482 mother-offspring pairs, overweight and obesity were observed in 6,516 offspring. Across increasing categories of pregnancy glycemia, the proportions of offspring with adolescent overweight/obesity increased: normoglycemia, 19%; abnormal GCT with normal OGTT, 22%; gestational IGT, 24%; and gestational diabetes, 25% (P < 0.0001). Corresponding odds ratios after adjustment for the mother's late adolescent characteristics (sociodemographic confounders and BMI) and pregnancy age were 1.2 (95% CI 1.1-1.4), 1.3 (1.2-1.5), and 1.4 (1.3-1.6), respectively. Further adjustment for offspring birth weight percentile and sociodemographic variables did not materially change results. Associations were more pronounced with increasing obesity severity.

CONCLUSIONS

Gestational glucose intolerance, including categories not meeting the gestational diabetes threshold, was associated with increased odds for offspring overweight/obesity at late adolescence.

Personality disorders and cause-specific mortality: a nationwide study of 2 million adolescents

BACKGROUND

Personality disorders are prevalent in 6-10% of the population, but their risk for cause-specific mortality is unclear. The aim of the study was to assess the association between personality disorders diagnosed in late adolescence and all-cause as well as cause-specific (cardiovascular-related, external-related) mortality.

METHODS

We performed a longitudinal study on a historical prospective cohort based on nationwide screening prior to recruitment to the Israeli army. The study participants were 16-19-year-old persons who attended the army screening (medical and cognitive, including screening for psychiatric disorders) between 1967 and 2006. Participants were followed from 1967 till 2011.

RESULTS

The study included 2 051 606 subjects, of whom 1 229 252 (59.9%) were men and 822 354 (40.1%) were women, mean age 17.36 years. There were 55 508 (4.5%) men and 8237 (1.0%) women diagnosed with personality disorders. The adjusted hazard ratio (HRs) for coronary, stroke, cardiovascular, external-related causes and all-cause mortality among men with personality disorders were 1.34 (1.03-1.74), 1.82 (1.20-2.76), 1.45 (1.23-1.71), 1.41 (1.30-1.53) and 1.44 (1.36-1.51), respectively. The absolute rate difference for all-cause mortality was 56.07 and 13.19 per 10⁵ person-years among men and women, respectively. Among women with personality disorders, the adjusted HRs for external-related causes and all-cause mortality were 2.74 (1.87-4.00) and 2.01 (1.56-2.58). Associations were already evident within 10 years of follow-up.

CONCLUSIONS

Personality disorder in late adolescence is associated with increased risk of cardiovascular, external- and all-cause mortality. Increased cardiovascular mortality is evident before the age of 40 years and may point to the importance of lifestyle education already in youth.