Advancing precision public health for obesity in children.

Worldwide, far too many children and adolescents are living with the disease of obesity. Despite decades of public health initiatives, rates are still rising in many countries. This raises the question of whether precision public health may be a more successful approach to preventing obesity in youth. In this review, the objective was to review the literature on precision public health in the context of childhood obesity prevention and to discuss how precision public health may advance the field of childhood obesity prevention. As precision public health is a concept that is still evolving and not fully identifiable in the literature, a lack of published studies precluded a formal review. Therefore, the approach of using a broad interpretation of precision public health was used and recent advances in childhood obesity research in the areas of surveillance and risk factor identification as well as intervention, evaluation and implementation using selected studies were summarized. Encouragingly, big data from a multitude of designed and organic sources are being used in new and innovative ways to provide more granular surveillance and risk factor identification in obesity in children. Challenges were identified in terms of data access, completeness, and integration, ensuring inclusion of all members of society, ethics, and translation to policy. As precision public health advances, it may yield novel insights that can contribute to strong policies acting in concert that ultimately lead to the prevention of obesity in children.

Birthweight, childhood body size, and timing of puberty and risks of breast cancer by menopausal status and tumor receptor subtypes.

BACKGROUND: Associations of birthweight, childhood body size and pubertal timing with breast cancer risks by menopausal status and tumor receptor subtypes are inconclusive. Thus, we investigated these associations in a population-based cohort of Danish women. METHODS: We studied 162,419 women born between 1930 and 1996 from the Copenhagen School Health Records Register. The register includes information on birthweight, measured childhood weights and heights at the age of 7-13 years, and computed ages at the onset of the growth spurt (OGS) and at peak height velocity (PHV). The Danish Breast Cancer Cooperative Group database provided information on breast cancer (n = 7510), including estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2) and menopausal status. Hormone replacement therapy use came from the Danish National Prescription Registry. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox regression. RESULTS: We found that birthweight was not associated with any breast cancer subtypes. While childhood BMI was not statistically significantly associated with ER+ tumors nor consistently with ER- tumors among pre-menopausal women, consistent inverse associations were found among postmenopausal women. At the age of 7 years, the HRs for postmenopausal ER+ and ER- tumors were 0.90 (95% CI 0.87-0.93) and 0.84 (95% CI 0.79-0.91) per BMI z-score, respectively. Similarly, childhood BMI was inversely associated with pre- and postmenopausal HER2- tumors, but not with HER2+ tumors. Childhood height was positively associated with both pre- and postmenopausal ER+ tumors, but not with ER- tumors. At the age of 7 years, the HRs for postmenopausal ER+ and ER- tumors were 1.09 (95% CI 1.06-1.12) and 1.02 (95% CI 0.96-1.09) per height z-score, respectively. In general, childhood height was positively associated with HER2+ and HER2- tumors among pre- and postmenopausal women. Ages at OGS and PHV were not associated with any breast cancer subtypes. CONCLUSIONS: We showed that a high BMI and short stature in childhood are associated with reduced risks of certain breast cancer subtypes. Thus, childhood body composition may play a role in the development of breast cancer.

Trajectories of Infant Weight Gain from Birth to 12 Months and Adult-Onset Coronary Heart Disease.

OBJECTIVE: To investigate associations between infant weight gain trajectories and coronary heart disease (CHD). STUDY DESIGN: We followed 3645 Danish individuals born between 1959 and 1961 with information on weight at birth and at age 2 weeks and 1, 2, 3, 4, 6, or 12 months. Sex-specific weight trajectories were generated using latent class modeling. Cases of CHD (n = 279) were identified from national health registers. Hazard ratios (HRs) were estimated by Cox regression with sequential adjustment for sex, socioeconomic status, prepregnancy body mass index, maternal smoking, preterm birth, parity, and birth weight. RESULTS: We identified 5 trajectories of weight development in infancy in our cohort: very low-moderate increase (11.5% of the population), low-marked increase (13.9%), low-stable increase (32.4%), average-stable increase (29.8%), and high-moderate increase (12.4%). Compared with the average-stable increasing trajectory, having a very low-moderately increasing weight trajectory in infancy was associated with a higher frequency of adult CHD (HR, 1.56; 95% CI, 1.04-2.33). The higher frequency remained after adjustment for maternal factors but was slightly attenuated after additional adjustment for preterm birth and parity (HR, 1.41; 95% CI, 0.91-2.23) and disappeared after adjustment for birth weight (HR, 0.78; 95% CI, 0.44-1.37). The associations with CHD did not differ between the other trajectories and the average-stable increasing trajectory. CONCLUSIONS: Although a pattern of very low-moderate increasing weight during infancy was associated with a higher frequency of adult CHD, the association did not persist after adjustment for birth weight, highlighting the importance of prenatal exposures.

Early life body size, pubertal timing, and risks of benign breast disease in a large cohort of Danish female adolescents and women.

A high childhood body mass index (BMI) may be protective against benign breast disease (BBD), but little is known about the effects of other early life body size measures. Thus, we examined associations between birthweight, childhood BMI, height, and pubertal timing and BBD risks. We included 171,272 girls, born from 1930 to 1996, from the Copenhagen School Health Records Register, which contains information on birthweight, childhood anthropometry (7-13 years), age at onset of the growth spurt (OGS), and peak height velocity (PHV). During follow-up, 9361 BBD cases (15-50 years) were registered in the Danish National Patient Register. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox regressions. At all childhood ages, BMI was inversely but non-linearly associated with BBD. The association was slightly stronger in magnitude for BMI z-scores above 0 (HRage 7 = 0.86; 95%CI: 0.83-0.90 per z-score) than below 0 (HRage 7 = 0.95; 95%CI 0.91-0.99 per z-score). Associations between childhood height and BBD differed by age; at 7 years the association was an inverted U-shape, whereas at 13 years height was not associated with BBD. Ages at OGS and PHV were positively associated with BBD. Low and high birthweights were associated with lower BBD risks.   Conclusion: A high childhood BMI, a short or tall stature at young childhood ages, an early pubertal onset, and low or high birthweights are associated with reduced risks of BBD. These complex associations suggest that the role of these factors in breast tissue development during early life warrants further investigation in relation to BBD etiology. What is Known: • Benign breast disease (BBD) is common and may be an intermediary marker of breast cancer risks. • Early life body size may relate to the development of BBD, but currently little is known. What is New: • Girls with a high body mass index at school ages or with an early pubertal timing have decreased risks of BBD. • Short and tall heights at young childhood ages and low and high birthweights are associated with lower BBD risks.

Change in Overweight from Childhood to Early Adulthood and Risk of Type 2 Diabetes.

BACKGROUND: Childhood overweight is associated with an increased risk of type 2 diabetes in adulthood. We investigated whether remission of overweight before early adulthood reduces this risk. METHODS: We conducted a study involving 62,565 Danish men whose weights and heights had been measured at 7 and 13 years of age and in early adulthood (17 to 26 years of age). Overweight was defined in accordance with Centers for Disease Control and Prevention criteria. Data on type 2 diabetes status (at age ≥30 years, 6710 persons) were obtained from a national health registry. RESULTS: Overweight at 7 years of age (3373 of 62,565 men; 5.4%), 13 years of age (3418 of 62,565; 5.5%), or early adulthood (5108 of 62,565; 8.2%) was positively associated with the risk of type 2 diabetes; associations were stronger at older ages at overweight and at younger ages at diagnosis of type 2 diabetes. Men who had had remission of overweight before the age of 13 years had a risk of having type 2 diabetes diagnosed at 30 to 60 years of age that was similar to that among men who had never been overweight (hazard ratio, 0.96; 95% confidence interval [CI], 0.75 to 1.21). As compared with men who had never been overweight, men who had been overweight at 7 and 13 years of age but not during early adulthood had a higher risk of type 2 diabetes (hazard ratio, 1.47; 95% CI, 1.10 to 1.98), but their risk was lower than that among men with persistent overweight (hazard ratio [persistently overweight vs. never overweight], 4.14; 95% CI, 3.57 to 4.79). An increase in body-mass index between 7 years of age and early adulthood was associated with an increased risk of type 2 diabetes, even among men whose weight had been normal at 7 years of age. CONCLUSIONS: Childhood overweight at 7 years of age was associated with increased risks of adult type 2 diabetes only if it continued until puberty or later ages. (Funded by the European Union.).

Birthweight, childhood overweight, height and growth and adult cancer risks: a review of studies using the Copenhagen School Health Records Register.

BACKGROUND: Most identified risk factors for cancer primarily occur in adulthood. As cancers generally have long latency periods, it is possible that risk factors acting earlier in life and accumulation of risks across the life course are important. Thus, focusing only on adult overweight as a modifiable risk factor may overlook childhood as an important aetiologic time window when body size is relevant for future cancer risks. The objective of this study was to review the evidence for associations between birthweight, body mass index (BMI), height and growth from 7-13 years and adult cancer risks based on studies using the Copenhagen School Health Records Register. METHODS: The register contains measured anthropometric information on 372,636 children born in 1930-1989. All studies examining associations between early life body size and risks of adult cancer (until 85 years, diagnosed in 1968-2015) were included, comprising 31 studies on 16 different cancer sites. Cancer diagnoses were retrieved via individual-level linkages to the Danish Cancer Registry. RESULTS: Birthweight was differentially associated with bladder, breast, colon, glioma, Hodgkin's disease, liver, kidney (renal cell), melanoma, ovarian, rectal, testicular and thyroid cancer. BMI in childhood was positively associated with risks of bladder (only late childhood), colon, endometrial, kidney, liver, oesophageal (only late childhood), ovarian, pancreatic (<70 years), prostate (only before childhood height adjustment) and thyroid cancer, whereas it was inversely associated with breast cancer. Child height was positively associated with breast, colon, endometrial, glioma, Hodgkin's disease, kidney, melanoma, oesophageal (only women), ovarian, prostate, testicular and thyroid cancer and inversely associated with bladder cancer. Greater than average increases in childhood BMI or linear growth at ages 7-13 increased risks of several cancers. CONCLUSIONS: Early life body size and growth are associated with many, but not all adult cancers, suggesting that the aetiology of several cancers may lie earlier in life than previously thought.

Body mass index and height in relation to type 2 diabetes by levels of intelligence and education in a large cohort of Danish men.

Socioeconomic status (SES) is inversely associated with risks of type 2 diabetes (T2D). We investigated if young men's cognitive function, measured by intelligence test scores and educational level, as determinants of SES modified associations between body mass index (BMI) and height with the risk of T2D. 369 989 young men from the Danish Conscription Database born between 1939 and 1959 with information on measured height, weight, intelligence test scores, and education were linked to the Danish National Patient Register. During follow-up from 1977 through 2015, T2D was recorded in 32 188 men. Hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated by Cox regressions. BMIs below-average (z-scores ≤ 0) were not related to risks of T2D. For BMIs above-average (z-scores > 0), positive associations between BMI and T2D were slightly stronger among men with higher intelligence test scores or longer educations than among men with lower levels of these factors (pinteraction-values < 0.004). Irrespective of BMI, incidence rates of T2D were higher among men with low levels of intelligence test score and education. Height was inversely associated with T2D (per z-score, HR = 0.96 (95% CI 0.95-0.97) and the association did not vary by intelligence test scores or education (all pinteraction-values > 0.59). While below-average BMI was not associated with T2D risk, above-average BMIs were and these association were stronger among men with high cognitive function. Nevertheless, T2D risk was higher at lower levels of cognitive function throughout the range of BMI. Height was inversely associated with T2D and it was not modified by cognitive function.

Levels of and Changes in Childhood Body Mass Index in Relation to Risk of Atrial Fibrillation and Atrial Flutter in Adulthood.

Children with obesity have a cardiometabolic risk profile that may predispose them to cardiovascular diseases. We examined the associations of childhood body mass index (BMI) and changes in BMI with the risk of atrial fibrillation and flutter (AFF) in adulthood. We conducted a population-based cohort study of Danish schoolchildren aged 7-13 years born from 1930 to 1989. Among 314,140 children, 17,594 were diagnosed with AFF as adults (1977-2014). In both men and women, above-average BMIs in childhood were associated with increased risks of AFF. Children who were persistently heavy at ages 7 and 13 years and children whose BMIs increased from the internal 25.0th-75.0th percentiles or from the internal 75.1th-90.0th percentiles between ages 7 and 13 years had higher risks of AFF in adulthood than children whose BMIs remained in the internal 25.0th-75.0th percentiles at both ages. A decrease in BMI percentile categories between 7 and 13 years of age reduced risks of AFF in adulthood, with risks of AFF reverting to levels similar to those in the reference group for women but not for men. In conclusion, risks of AFF in adulthood increased with higher childhood BMIs. Remission from overweight by age 13 years reduced AFF risks, especially in women.

Breastfeeding duration in infancy and adult risks of type 2 diabetes in a high-income country.

Observed associations between breastfeeding and reduced risk of type 2 diabetes in adulthood may be confounded. We examined if the duration of breastfeeding in infancy was associated with the risk of type 2 diabetes in adulthood after adjustment for a range of prenatal and postnatal risk factors. We prospectively followed 6,044 individuals from the Copenhagen Perinatal Cohort born 1959-1961. Duration of any breastfeeding (≤0.5, >0.5-1, >1-2, >2-4, >4 months) was assessed at the infant's 1-year health examination. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs) for type 2 diabetes (at age ≥30 years, 237 persons) by breastfeeding duration without and with adjustment for parental social status and education, maternal pre-pregnancy body mass index (BMI), maternal diabetes and smoking during pregnancy, gestational weight gain, parity, preterm birth, birth weight, sex, and BMI at ages 7 and 41-43 years. In the unadjusted analysis, compared with infants breastfed for ≤0.5 month, those breastfed for >4 months had a 51% reduced risk of type 2 diabetes (HR = 0.49; 95% CI [0.32, 0.75]). After the stepwise adjustment for putative early life confounders, this was attenuated to a nonsignificant 31% reduced risk (HR = 0.69; 95% CI [0.44, 1.07]). Adjustment for childhood and adulthood BMI minimally changed the results. We found that the inverse association between the duration of breastfeeding and risk of type 2 diabetes in adulthood is considerably weakened and no longer significant after adjustment for prenatal and postnatal factors in the infant and mother.

Change in weight status from childhood to early adulthood and late adulthood risk of colon cancer in men: a population-based cohort study.

BACKGROUND: Although weight gain in mid- to late adult life is associated with an increased risk of colon cancer, it is unclear if increases or losses in weight from childhood to early adulthood are differentially associated with risks of adult colon cancer. METHODS: Weight and height were measured at 7 or 13 years and in early adulthood (17-26 years) in 64,675 boys in the Copenhagen School Health Records Register and the Danish Conscription Database. Cases of colon cancer (n = 751) were identified in the Danish Cancer Registry. Boys and young men were categorized as normal weight or overweight. Associations between changes in weight and colon cancer were examined using Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Compared with men with a normal weight at 7 years and in early adulthood, men with overweight at both ages had an increased risk of adult colon cancer (HR: 2.73, 95% CI 1.80-4.15). In contrast, men with overweight at 7 years, but not in early adulthood did not have an increased risk of colon cancer (HR: 0.73, 95% CI 0.35-1.54), nor did men with a normal weight at 7 years and overweight in early adulthood (HR: 1.28, 95% CI 0.96-1.70). Similar results were observed for weight status at age 13 years combined with early adulthood. CONCLUSIONS: Childhood overweight that persists into early adulthood is associated with an increased risk of colon cancer, whereas overweight that disappears before early adulthood or developed after childhood is not.

Antibiotic exposure in early life and childhood overweight and obesity: A systematic review and meta-analysis.

We conducted a systematic review and meta-analysis of observational studies investigating the association between antibiotic exposure in infancy and risk of childhood overweight and obesity. Thirteen studies, including a total of 527 504 children, were included in the systematic review and 8 were included in meta-analyses. Exposure to antibiotics in infancy was associated with an increased odds ratio (OR) of childhood overweight and obesity (OR 1.11, 95% confidence interval [CI] 1.02-1.20). Whereas exposure to 1 treatment only and exposure between 6 and 24 months were not associated with increased risk of childhood overweight and obesity, exposure to >1 treatment was associated with an OR of 1.24 (95% CI 1.09-1.43) and exposure within the first 6 months of life was associated with an OR of 1.20 (95% CI 1.04-1.37). In conclusion, antibiotic exposure in infancy was associated with a slightly increased risk of childhood overweight and obesity, mainly if children were exposed to repeated treatments or treatment within the first 6 months of life. It is unclear whether this association is mediated via direct effects of antibiotics on the gut microbiota.

Height at Ages 7-13 Years in Relation to Developing Type 2 Diabetes Throughout Adult Life.

BACKGROUND: Short adults have an increased risk of type 2 diabetes. Although adult height results from childhood growth, the effects of height and growth trajectories during childhood are sparsely investigated. We investigated sex-specific associations between childhood height, growth and adult type 2 diabetes, including potential influences of birthweight and childhood body mass index (BMI). METHODS: We followed 292 827 individuals, born 1930-83, from the Copenhagen School Health Records Register in national registers for type 2 diabetes (11 548 men; 7472 women). Weights and heights were measured at ages 7-13 years. Hazard ratios (HR) of type 2 diabetes (age ≥30 years) were estimated without and with adjustment for birthweight and BMI. RESULTS: In men, associations between height and type 2 diabetes changed from inverse for below-average heights at age 7 years to positive for above-average heights at 13 years. No consistent associations were observed among women. These associations were not affected by birthweight. After adjustment for BMI, below-average childhood heights were inversely associated with type 2 diabetes among men (HR range: 0.91-0.93 per z-score) but above-average heights were not. Among women, after adjustment for BMI, below- and above-average heights in childhood were inversely associated with type 2 diabetes (HR range: 0.91-0.95). Greater height growth from 7 to 13 years was positively associated with type 2 diabetes in men and women. CONCLUSIONS: After adjustment for BMI, short childhood height at all ages and greater growth during childhood are associated with an increased risk of type 2 diabetes, suggesting that this period of life warrants mechanistic investigations.

Early life body size and puberty markers as predictors of breast cancer risk later in life: A neural network analysis.

BACKGROUND: The early life factors of birthweight, child weight, height, body mass index (BMI) and pubertal timing are associated with risks of breast cancer. However, the predictive value of these factors in relation to breast cancer is largely unknown. Therefore, using a machine learning approach, we examined whether birthweight, childhood weights, heights, BMIs, and pubertal timing individually and in combination were predictive of breast cancer. METHODS: We used information on birthweight, childhood height and weight, and pubertal timing assessed by the onset of the growth spurt (OGS) from 164,216 girls born 1930-1996 from the Copenhagen School Health Records Register. Of these, 10,002 women were diagnosed with breast cancer during 1977-2019 according to a nationwide breast cancer database. We developed a feed-forward neural network, which was trained and tested on early life body size measures individually and in various combinations. Evaluation metrics were examined to identify the best performing model. RESULTS: The highest area under the receiver operating curve (AUC) was achieved in a model that included birthweight, childhood heights, weights and age at OGS (AUC = 0.600). A model based on childhood heights and weights had a comparable AUC value (AUC = 0.598), whereas a model including only childhood heights had the lowest AUC value (AUC = 0.572). The sensitivity of the models ranged from 0.698 to 0.760 while the precision ranged from 0.071 to 0.076. CONCLUSION: We found that the best performing network was based on birthweight, childhood weights, heights and age at OGS as the input features. Nonetheless, this performance was only slightly better than the model including childhood heights and weights. Further, although the performance of our networks was relatively low, it was similar to those from previous studies including well-established risk factors. As such, our results suggest that childhood body size may add additional value to breast cancer prediction models.

A literature review of evidence for primary prevention of overweight and obesity in healthy weight children and adolescents: A report produced by a working group of the Danish Council on Health and Disease Prevention.

Primary prevention targets development of overweight in individuals with healthy weight and is a great challenge. This paper summarizes the main findings of a working group of the Danish Council on Health and Disease Prevention that reviewed the literature on primary prevention of overweight and obesity among children and adolescents. The results were presented in a Danish report, in which a 2019 Cochrane review on childhood obesity prevention was complemented by searches in PubMed to include all relevant subsequent studies published from January 2018 until March 2020. In this paper, the review was updated until June 2023. Numerous childhood overweight prevention interventions have been developed during the past decades, primarily targeting diet and/or physical activity. Several of these interventions showed positive effects on diet and physical activity level but did not show effects on risk of developing overweight. The evidence foundation is inconsistent as four out of five interventions did not show positive effects. Previously observed intervention effects may not reflect excessive weight gain prevention among children with healthy weight but rather bodyweight reduction among those with overweight or obesity. We do not have sufficient knowledge about how to prevent children with healthy weight from developing overweight, and creative solutions are urgently needed.

Associations of maternal birth weight, childhood height, BMI, and change in height and BMI from childhood to pregnancy with risks of preterm delivery.

BACKGROUND: It remains unknown whether maternal early life body size and changes in height and BMI from childhood to pregnancy are associated with risks of having a preterm delivery. OBJECTIVES: We investigated whether a woman's birth weight, childhood height, BMI, and changes in height and BMI from childhood to pregnancy were associated with preterm delivery. METHODS: We studied 47,947 nulliparous women born from 1940 to 1996 who were included in the Copenhagen School Health Records Register with information on birth weight and childhood heights and weights at ages 7 and/or 13 years. Gestational age was obtained from the Danish Birth Register, as was prepregnancy BMI, for 13,114 women. Deliveries were classified as very (22 to <32 weeks) or moderately (32 to <37 weeks) preterm. Risk ratios (RRs) and 95% CIs were estimated using binomial regression. RESULTS: A woman's birth weight and childhood height were inversely associated with having very and moderately preterm delivery. Childhood BMI had a U-shaped association with having a very preterm delivery; at age 7 years, compared to a BMI z score of 0, the RRs were 1.31 (95% CI, 1.11-1.54) for a z score of -1 and 1.18 (95% CI, 1.01-1.38) for a z score of +1. Short stature in childhood and adulthood was associated with higher risks of very and moderately preterm delivery. Changing from a BMI at the 85th percentile at 7 years (US CDC reference) to a prepregnancy BMI of 22.5 kg/m2 was associated with RRs of 1.12 (95% CI, 0.91-1.37) and 0.88 (95% CI, 0.78-0.99) for very and moderately preterm delivery, respectively, compared to a reference woman at the 50th percentile at 7 years (22.5 kg/m2 prepregnancy BMI). CONCLUSIONS: Maternal birth weight, childhood height, and BMI are associated with very and moderately preterm delivery, although in different patterns. Consistent short stature is associated with very and moderately preterm delivery, whereas normalizing BMI from childhood to pregnancy may reduce risks of having a very preterm delivery.

Body mass index trajectories in childhood and incidence rates of type 2 diabetes and coronary heart disease in adulthood: A cohort study.

AIMS: We examined associations between five body mass index (BMI) trajectories from ages 6-15 years and register-based adult-onset type 2 diabetes mellitus (T2D) and coronary heart disease (CHD) with and without adjustment for adult BMI. METHODS: Child and adult BMI came from two Danish cohorts and 13,205 and 13,438 individuals were included in T2D and CHD analyses, respectively. Trajectories were estimated by latent class modelling. Incidence rate ratios (IRRs) were estimated with Poisson regression. RESULTS: In models without adult BMI, compared to the lowest trajectory, among men the T2D IRRs were 0.92 (95 %CI:0.77-1.09) for the second lowest trajectory and 1.51 (95 %CI:0.71-3.20) for the highest trajectory. The corresponding IRRs in women were 0.92 (95 %CI:0.74-1.16) and 3.58 (95 %CI:2.30-5.57). In models including adult BMI, compared to the lowest trajectory, T2D IRRs in men were 0.57 (95 %CI:0.47-0.68) for the second lowest trajectory and 0.26 (95 %CI:0.12-0.56) for the highest trajectory. The corresponding IRRs in women were 0.60 (95 %CI:0.48-0.75) and 0.59 (95 %CI:0.36-0.96). The associations were similar in direction, but not statistically significant, for CHD. CONCLUSIONS: Incidence rates of adult-onset T2D were greater for a high child BMI trajectory than a low child BMI trajectory, but not in models that included adult BMI.

Risk of gestational diabetes mellitus in nulliparous women - Associations with early life body size and change in body mass index from childhood to adulthood.

AIMS: We examined whether a woman's birthweight, childhood height, body mass index (BMI), and BMI changes from childhood to pregnancy were associated with risks of gestational diabetes mellitus (GDM). METHODS: We studied 13,031 women from the Copenhagen School Health Records Register born 1959-1996 with birthweight and measured anthropometric information at ages 7 and/or 13. The diagnosis of GDM (n = 255) was obtained from a national health register. Risk ratios (RR) were estimated using log-linear binomial regression. RESULTS: Own birthweight and childhood height were inversely associated with GDM. Girls with overweight at age 7 had a higher risk of GDM than girls with normal-weight (RR: 1.79, 95% CI: 1.31, 2.47). Compared to women with normal-weight in childhood and adulthood, risks of GDM were higher in women who developed overweight from age 7 to pregnancy (RR: 4.62; 3.48, 6.14) or had overweight at both times (RR: 4.71; 3.24, 6.85). In women whose BMI normalized from age 7 to pregnancy the RR for GDM was 1.08 (0.47, 2.46). CONCLUSIONS: Lower birthweight, shorter childhood height, and higher childhood BMI are associated with increased risks of GDM. Efforts to help girls maintain a normal BMI before pregnancy may be warranted to minimize risks of GDM.

Associations between body mass index and height during childhood and adolescence and the risk of coronary heart disease in adulthood: A systematic review and meta-analysis.

Body mass index (BMI) at child and adolescent ages is positively associated with adult coronary heart disease (CHD) whereas height at these ages may be inversely associated with CHD. However, potential effects of age, sex, and socioeconomic status on associations between BMI and CHD are less investigated. We conducted a systematic review and meta-analysis of BMI and height at ages 2-19 years in relation to adult CHD and examined effects of age, sex, socioeconomic status, and other factors. Twenty-two studies on BMI and five on height were included, comprising 5,538,319 individuals and 69,830 CHD events. Random effects meta-analyses were conducted. Child and adolescent BMI were positively associated with CHD (hazard ratio = 1.12; 95% confidence interval [CI] [1.01, 1.25] per standard deviation [SD]), and categorical analyses supported these findings. The associations did not significantly differ by age, sex, or by adjustment for socioeconomic status. Child and adolescent height were inversely associated with CHD (hazard ratio = 0.87; 95% CI [0.81, 0.93] per SD), and categorical analyses agreed. Insufficient studies on height precluded subgroup analyses. Heterogeneity was generally high in all analyses. We found that BMI in youth is positively associated with adult CHD regardless of sex or adjustment for socioeconomic status whereas height is inversely associated with later risk of CHD.