Relationship between early puberty and the risk of hypertension/overweight at age 50: evidence for a modified Barker hypothesis among Polish youth

Lifelong impacts of puberty timing on human plasma metabolic profiles: A metabolome-wide Mendelian randomization study

AIM

The aim was to investigate the causal relationship between puberty timing and plasma metabolites, accounting for birth weight, childhood and adulthood adiposity.

MATERIALS AND METHODS

The meta-analysis of genome-wide association studies (GWAS) for puberty timing was extracted from the ReproGen Consortium, involving 329 345 women of European ancestry. Summary data for 174 plasma metabolites were retrieved from a recently conducted cross-platform GWAS that involved a meta-analysis of three cohort studies (i.e. the Fenland, European Prospective Investigation into Cancer-Norfolk and INTERVAL studies) and three publicly available studies and included up to 86 507 participants. We conducted a two-sample Mendelian randomization (MR) analysis to infer the causal relationship of puberty timing on 174 plasma metabolites, complemented by a two-step and multivariable Mendelian randomization (MVMR) analysis to assess direct and indirect effects. Additionally, summary-level data from the UK Biobank were used for our replication analysis.

RESULTS

The results of the two-sample MR provide moderate evidence supporting a causal relationship between puberty timing and 23 of 174 plasma metabolites (i.e. 7 acylcarnitines, 8 amino acids, 2 biogenic amines and 6 lysophosphatidylcholines). Even after single-nucleotide polymorphisms associated with birth weight and childhood adiposity were excluded, causal effects persisted for 16 metabolites (i.e. 8 acylcarnitines, 4 amino acids, 2 biogenic amines and 2 lysophosphatidylcholines). The two-step MR analysis provided evidence that the relationship between puberty timing and plasma metabolites was mediated by adulthood adiposity. Additionally, moderate evidence emerged for an independent causal effect of puberty timing on 10 metabolites through an MVMR analysis (i.e. 5 acylcarnitines, 2 amino acids, 1 biogenic amine, 1 lysophosphatidylcholine and 1 phosphatidylcholine). Furthermore, the replication analysis suggested the robustness of our results.

CONCLUSIONS

In summary, our study provides compelling evidence that puberty timing has a causal influence on certain plasma metabolites, although this influence is largely mediated by adulthood adiposity.

Associations of central precocious puberty with blood pressure trajectories: prospective cohort study

BACKGROUND

Sex differences in blood pressure (BP) appear during childhood and adolescence, but the role of central precocious puberty (CPP) remains unclear. In this study, we aimed to examine the association of CPP with the risk of early hypertension and BP trajectories in girls and boys.

METHODS

We analyzed trajectories of BP before and after puberty in girls aged 6-13 years (n = 305) and boys aged 10-15 years (n = 153) in the Taiwan Pubertal Longitudinal Study. The timing of puberty onset was defined as the month at which the children reached Tanner stage 2. We examined the association of CPP with the risk of early hypertension and BP trajectories before and after puberty onset.

RESULTS

Among boys, CPP was found to be associated with early hypertension (odds ratio, 7.45 [95% CI, 1.15-48.06]), whereas no such association was observed among girls. Boys with CPP had higher systolic BP than did those with normal puberty onset before puberty onset (mean difference, 6.51 [95% CI, 0.58-12.43]) and after puberty onset (mean difference, 8.92 [95% CI, 8.58-15.26]).

CONCLUSION

A large proportion of the higher systolic BP observed in boys with CPP compared with in those with normal puberty onset is accrued after puberty.

IMPACT

We examined the sex-specific association of central precocious puberty with blood pressure trajectories to better understand whether central precocious puberty was associated with early hypertension. Central precocious puberty was associated with differences in systolic blood pressure trajectories, especially after puberty onset in boys. For boys only, central precocious puberty was associated with early hypertension. A large proportion of the higher systolic blood pressure observed in boys with central precocious puberty compared with in those with normal puberty onset was accrued after puberty. Interventions targeting central precocious puberty are likely to influence systolic blood pressure in early adulthood.

Association between age at menarche and cardiometabolic risk among Samoan adults

OBJECTIVES

Recent studies suggest that early menarche may increase cardiometabolic morbidity and mortality. Yet few studies have examined this association in the Pacific Islands, where obesity prevalence is among the highest globally. We sought to examine associations between age at menarche and cardiometabolic risk in Samoa.

METHODS

Participants were from the Soifua Manuia study (n = 285, age 32-72 years) conducted in Samoa from 2017 to 2019. Logistic regressions were conducted to estimate odds of obesity, hypertension, diabetes, dyslipidemia, and metabolic syndrome per one-year increase in age at menarche. Linear regressions were conducted to examine associations between age at menarche and continuous measures of adiposity, blood pressure, insulin resistance, and serum lipids.

RESULTS

Median age at menarche was 14 years (IQR = 2). After controlling for relevant covariates, each one-year increase in age at menarche was associated with a 15% decrease (OR = 0.85, 95% CI: 0.72-1.01, p = .067) in odds of hypertension, but a 21% increase (OR = 1.21, 95% CI: 1.01-1.45, p = .044) in odds of diabetes and 18% increase (OR = 1.18, 95% CI: 0.98-1.42, p = .081) in odds of high total cholesterol. Each additional year in age at menarche was associated with a 1.60 ± 0.52 kg (p = .002) decrease in lean mass and 1.56 ± 0.51 kg (p = .003) decrease in fat-free mass.

CONCLUSIONS

Associations between age at menarche and cardiometabolic risk may be population-specific and are likely influenced by both current and historical nutritional and epidemiological contexts. Prospective studies are needed to clarify the role of childhood adiposity and other early life exposures on age at menarche and subsequent cardiometabolic risk.

The long-lasting effect of early life family structure on social position, well-being, and biological condition in adulthood

BACKGROUND

The absence of even one parent has short- and long-term effects on the child's current and future health. The purpose of the study was to determine whether there is a long-term relationship between the type of family in which men were raised and an individual's adult social position, well-being in adulthood and their biological condition regardless of social status in adulthood.

MATERIALS AND METHODS

Data for 4528 males, aged 25-80 years, were selected from the archives of the Lower Silesian Medical Centre in Wrocław, Poland. A total of 329 men declared that they grew up in incomplete families. Height, weight, % fat, cardiovascular and respiratory systems, blood parameters, and health of men who grew up in complete or incomplete families were compared.

RESULTS

Growing up in an incomplete family reduced chances for better education, decreased life satisfaction in adulthood, and negatively affected the final height. After taking into account the education achieved, the effect persisted only for diastolic blood pressure, creatinine, and serum phosphorus levels.

CONCLUSIONS

Growing up in an incomplete family has a significant impact on male's socioeconomic position (SES), life satisfaction, and final height. A poorer quality of diet is proposed as an early life risk factor for adult health.

The Association of Accelerated Early Growth, Timing of Puberty, and Metabolic Consequences in Children

Accelerated early growth and early timing of puberty or pubertal variant have been noticed as risk factors for metabolic syndrome, more frequently observed in children born small for gestational age (SGA) or children with premature adrenarche (PA). Children with SGA, especially if they make an accelerated catch-up growth in early life, carry a higher risk for long-term metabolic consequences, such as type 2 diabetes, insulin resistance, and cardiovascular diseases. Furthermore, multiple studies support that these children, either born SGA or with a history of PA, may have earlier pubertal timing, which is also associated with various metabolic risks. This review aims to summarize the recent studies investigating the association between early infantile growth, the timing of puberty, and metabolic risks to expand our knowledge and gain more insight into the underlying pathophysiology.

Persistent high exposure to exogenous phthalates and endogenous sex hormones associated with early pubertal onset among children: A 3.5-year longitudinal cohort study in China

BACKGROUND

Early onset of puberty could have significant impacts on childhood health, but the extent to which it was affected by phthalate esters (PAEs) and sex hormone disruption was not understood. The aim of this study is to investigate the associations between exposure to PAEs and sex hormone disruption and early onset of puberty in children.

METHODS

A longitudinal cohort study was conducted in China from May 2017 to Oct 2020, involving 740 children during consecutive visits. The onset of puberty was evaluated using Tanner definition, and early puberty was defined as an onset age less than the first 25 %, with cut-offs of 10.33 and 8.97 years for boys and girls, respectively. Serum testosterone (TT), estradiol (E₂) and urinary PAE metabolites were measured during three visits. Generalized linear models were used to explore the associations between PAE and sex hormones with the age of puberty onset, while log-binomial regressions were applied to assess the associations of persistent exposure to PAEs and sex hormones with early pubertal onset.

RESULTS

Approximately 86.0 % of boys and 90.2 % of girls completed puberty onset from pre-puberty, and more than 95 % of participants had PAE concentrations higher than the limit of detection. Boys showed higher exposure to PAE pollutants and higher TT levels. Persistent exposure to PAEs was positively associated with early pubertal onset in girls (ARR = 1.97, 95 %CI = 1.12, 3.46). Moreover, persistent exposure to PAEs and E₂ had synergistic associations with early pubertal onset in both boys (ARR = 4.77, 95 %CI = 1.06, 21.54) and girls (ARR = 7.07, 95 %CI = 1.51, 33.10). However, PAEs and TT had antagonistic associations only in boys (ARR = 0.44, 95 %CI = 0.07, 2.58).

CONCLUSION

Long-term exposure to PAEs might increase the risk of early pubertal onset, and it appears to work in synergy with E₂, while in antagonism with TT in boys' early pubertal onset. Reducing PAEs exposure might promote pubertal health.

Puberty Timing and Sex-Specific Trajectories of Systolic Blood Pressure: a Prospective Cohort Study

BACKGROUND

Sex differences in systolic blood pressure (SBP) emerge during adolescence but the role of puberty is not well understood. We examined sex-specific changes in SBP preceding and following puberty and examined the impact of puberty timing on SBP trajectories in females and males.

METHODS

Trajectories of SBP before and after puberty and by timing of puberty in females and males in a contemporary birth cohort study were analyzed. Repeated measures of height from age 5 to 20 years were used to identify puberty timing (age at peak height velocity). SBP was measured on ten occasions from 3 to 24 years (N participants, 4062; repeated SBP measures, 29 172). Analyses were performed using linear spline multilevel models based on time before and after puberty and were adjusted for parental factors and early childhood factors.

RESULTS

Mean age at peak height velocity was 11.7 years (SD, 0.8) for females and 13.6 years (SD, 0.9) for males. Males had faster rates of increase in SBP before puberty leading to 10.19 mm Hg (95% CI, 6.80-13.57) higher mean SBP at puberty which remained similar at 24 years (mean difference, 11.43 mm Hg [95% CI, 7.22-15.63]). Puberty timing was associated with small transient differences in SBP trajectories postpuberty in both sexes and small differences at 24 years in females only.

CONCLUSIONS

A large proportion of the higher SBP observed in males compared with females in early adulthood is accrued before puberty. Interventions targeting puberty timing are unlikely to influence SBP in early adulthood.

Obesity, metabolic syndrome, and primary hypertension

Primary hypertension is the dominant form of arterial hypertension in adolescents. Disturbed body composition with, among other things, increased visceral fat deposition, accelerated biological maturation, metabolic abnormalities typical for metabolic syndrome, and increased adrenergic drive constitutes the intermediary phenotype of primary hypertension. Metabolic syndrome is observed in 15-20% of adolescents with primary hypertension. These features are also typical of obesity-related hypertension. Metabolic abnormalities and metabolic syndrome are closely associated with both the severity of hypertension and the risk of target organ damage. However, even though increased body mass index is the main determinant of blood pressure in the general population, not every hypertensive adolescent is obese and not every obese patient suffers from hypertension or metabolic abnormalities typical for metabolic syndrome. Thus, the concepts of metabolically healthy obesity, normal weight metabolically unhealthy, and metabolically unhealthy obese phenotypes have been developed. The risk of hypertension and hypertensive target organ damage increases with exposure to metabolic risk factors which are determined by disturbed body composition and visceral obesity. Due to the fact that both primary hypertension and obesity-related hypertension present similar pathogenesis, the principles of treatment are the same and are focused not only on lowering blood pressure, but also on normalizing body composition and metabolic abnormalities.

Origins of Primary Hypertension in Children

Although relatively rare in childhood, primary hypertension (PH) is thought to have originated in childhood and may be even determined perinatally. PH prevalence increases in school-age children and affects 11% of 18-year-old adolescents. Associated with metabolic risk factors, elevated blood pressure in childhood is carried into adulthood. Analysis of the phenotype of hypertensive children has revealed that PH is a complex of anthropometric and neuro-immuno-metabolic abnormalities, typically found in hypertensive adults. Children with elevated blood pressure have shown signs of accelerated biological development, which are closely associated with further development of PH, metabolic syndrome, and cardiovascular disease in adulthood. At the time of diagnosis, hypertensive children were reported to have significant arterial remodelling expressed as significantly increased carotid intima-media thickness, increased stiffness of large arteries, lower area of microcirculation, and decreased endothelial function. These changes indicate that their biological age is 4 to 5 years older than their normotensive peers. All these abnormalities are typical features of early vascular aging described in adults with PH. However, as these early vascular changes in hypertensive children are closely associated with features of accelerated biological development and neuro-immuno-metabolic abnormalities observed in older subjects, it seems that PH in childhood is not only an early vascular aging event, but also an early biological maturation phenomenon.

The relationship between pubertal timing and markers of vascular and cardiac structure and function in men and women aged 60-64 years

Earlier age at menarche has been associated with higher risk of coronary heart disease, but the mechanisms underlying the association remain unclear. We assessed the relationship of pubertal timing, in both men (n = 672) and women (n = 713), with vascular (carotid intima-media thickness (cIMT), pulse wave velocity (PWV)) and cardiac (left ventricular (LV) structure and function) measures recorded at age 60–64 yrs in a British birth cohort study. Regression models found that earlier menarche was associated with higher (more adverse) LV mass, LV end diastolic volume and left atrial volume, but not with other cardiac measures, cIMT or PWV. Associations were attenuated after adjustment for either adult or childhood BMI (e.g. mean difference in LV mass per year later menarche: −4.2 g (95% CI:−7.0,−1.4) reducing to −2.2 g (95% CI:−4.7,0.4) after adjustment for adult BMI). There were no associations among men, despite those fully mature at 15 yrs having higher blood pressure than the least mature group by 10.21 mmHg (95% CI:19.45,0.98). Any effect of pubertal timing on vascular and cardiac structure and function is likely to be small and primarily confounded by pre-pubertal BMI and/or mediated through adult adiposity.

Race disparities in pubertal timing: Implications for cardiovascular disease risk among African American women

Compared to white girls, sexual maturation is accelerated in African American girls as measured by indicators of pubertal development, including age at first menses. Increasing epidemiological evidence suggests that the timing of pubertal development may have strong implications for cardio-metabolic health in adolescence and adulthood. In fact, younger menarcheal age has been related prospectively to poorer cardiovascular risk factor profiles, a worsening of these profiles over time, and an increase in risk for cardiovascular events, including non-fatal incident cardiovascular disease and cardiovascular-specific and all-cause mortality. Yet, because this literature has been limited almost exclusively to white girls/women, whether this same association is present among African American girls/women has not been clarified. In the current narrative review, the well-established vulnerability of African American girls to experience earlier pubertal onset is discussed as are findings from literatures examining the health outcomes of earlier pubertal timing and its antecedents, including early life adversity exposures often experienced disproportionately in African American girls. Gaps in these literatures are highlighted especially with respect to the paucity of research among minority girls/women, and a conceptual framework is posited suggesting disparities in pubertal timing between African American and white girls may partially contribute to well-established disparities in adulthood risk for cardio-metabolic disease between African American and white women. Future research in these areas may point to novel areas for intervention in preventing or lessening the heightened cardio-metabolic risk among African American women, an important public health objective.

Pubertal testis volume, age at pubertal onset, and adolescent blood pressure: Evidence from Hong Kong's "Children of 1997" birth cohort

OBJECTIVES

A warning from Health Canada suggests that testosterone increases blood pressure (BP). No evidence from large randomized controlled trials is available, and observational studies are confounded by ill-health lowering serum testosterone. To address the evidence gap, we assessed the association of pubertal testicular volume, as a reflection of testosterone production, with BP.

METHODS

We examined whether testicular volume was associated with sex-, age-, and height-standardized BP z-score at ∼13 years in a population-representative Chinese birth cohort (n = 5195, 63% follow-up). We used age at pubertal onset, determined as the earliest age when Tanner stage II for genitalia, breast, or pubic hair, or testicular volume of 4 mL occurred, as control exposures. These exposures were expected to produce findings different from testicular volume because they are not direct measures of testosterone. They were used to ascertain specificity of exposure and to detect residual confounding.

RESULTS

Greater testicular volume was associated with higher systolic BP by 0.03 z-score, which is equivalent to 1.40 mm Hg per standard deviation of testicular volume (95% CI 0.02-0.04), adjusted for infant characteristics, socioeconomic position, and childhood body mass index. Similarly adjusted, earlier pubertal onset was not associated with higher systolic BP z-score in boys or girls.

CONCLUSIONS

Greater pubertal testicular volume is related to higher BP, consistent with a potential role of androgens in the higher BP in boys than girls that emerges during puberty. Our finding provides preliminary evidence supportive of more definitive studies to clarify the warning on testosterone from Health Canada.

Maternal Age of Menarche and Blood Pressure in Adolescence: Evidence from Hong Kong's "Children of 1997" Birth Cohort

Background

Age of puberty has declined substantially in developed settings and is now declining in the rest of the world with economic development. Early age of puberty is associated with non-communicable diseases in adulthood, and may be a long-term driver of population health with effects over generations. In a non-Western setting, we examined the association of maternal age of menarche with blood pressure in late childhood/adolescence.

Methods

We used generalised estimating equations to estimate the adjusted association of maternal age of menarche with age-, sex- and height-adjusted blood pressure z-score from 10 to 16 years in Hong Kong’s population-representative birth cohort, “Children of 1997” (n = 8327). We also assessed whether associations were mediated by body mass index (BMI) or pubertal stage.

Results

Earlier maternal age of menarche was associated with higher systolic blood pressure in adolescence [-0.02 z-score per year older maternal age of menarche, 95% confidence interval (CI) -0.04 to -0.003]. The association of maternal age of menarche with systolic blood pressure was mediated by adiposity and/or pubertal stage at 11 years. Maternal age of menarche was not associated with diastolic blood pressure.

Conclusion

Earlier maternal age of puberty was associated with higher systolic blood pressure, largely mediated by adiposity, highlighting the importance of tackling childhood obesity as a public health priority in view of the secular trend of declining age of puberty.

Pubertal timing and a family history of hypertension: Prospective cohort study

BACKGROUND

Hypertension is heritable, and genetic factors likely exert an effect from childhood. Puberty is an early life milestone that may relate to adult hypertension. Therefore, this study examined whether there is an association between a family history of hypertension and pubertal growth.

METHODS

The participants were children from a prospective cohort study called Project Koshu, who were born between 1991 and 1998 in Japan. Data on family history of hypertension, maternal characteristics, birth and early life factors were collected from the questionnaire administered to the mothers at the time of pregnancy registration or medical check-up. Child age at peak height velocity (early or non-early) was calculated from the anthropometric data collected during annual school check-up.

RESULTS

Data on 919 children (479 boys and 440 girls) were included in the analysis; 478 participants had a family history of hypertension. After adjustment for potential confounders (birth month, maternal body mass index, maternal work status, maternal education, and paternal education), early age at peak height velocity was found to be associated with a family history of hypertension (OR, 1.52; 95% confidence interval (CI): 1.04-2.24; P = 0.03) and specifically, with having at least one maternal hypertensive relative (OR, 1.81; 95%CI: 1.23-2.68; P = 0.003).

CONCLUSIONS

Together with previous reports on the relationship between puberty and adult hypertension, the present results suggest that the timing of pubertal growth is involved in the process of hypertension development in people with a family history of hypertension. Further confirmative studies are needed.

Vascular Aging: Lessons From Pediatric Hypertension

Hypertension (HTN) in children is associated with early vascular aging (EVA) and underlying immunologic-metabolic abnormalities and accelerated biological maturation. Morphologic and functional vascular changes underlying EVA and HTN in children resemble those seen in the elderly including but not limited to an increase in intima-media thickness (IMT) and arterial stiffness and endothelial dysfunction. Although progeria syndrome leading to EVA and the development of clinically manifested cardiovascular (CV) disease in the second decade of life is a rare hereditary disorder, primary HTN, which is also associated with EVA, is much more common (reported in up to 10% in adolescents). EVA associated with HTN in children leads to the premature development of target organ injury in childhood and CV events in early adulthood. Limited evidence from prospective observational studies in children and adolescents indicates that early lifestyle measures (low salt/low sugar intake and exercise) or pharmacologic treatment of HTN, or both, partially reverses morphologic and functional changes underlying EVA such as an increase in carotid IMT and pulse wave velocity, a decrease in flow-mediated dilation of the brachial artery, and an increase in oxidative stress and visceral fat. Future mechanistic and therapeutic clinical trials are desirable to assess the mechanisms and treatment strategies of EVA in the context of HTN in children and their effect on CV events in early adulthood.

Secular trends in BMI and the prevalence of obesity in young Polish males from 1965 to 2010

BACKGROUND

Obesity is a serious public health problem, the prevalence of which is increasing dramatically all over the world. The aim of this study was to examine trends in body mass index (BMI) and the proportion of overweight and obese individuals among 19-year-old Polish males reporting for mandatory military fitness exams from 1965 to 2010.

METHODS

Height, weight and BMI [weight (kg)/height (m(2))] in five 10% nationwide random samples of 19-year-old conscripts examined in 1965, 1986, 1995, 2001 and 2010 were analysed.

RESULTS

From 1965 to 2010, mean BMI in 19-year-old Polish males increased from 21.7 to 22.9. The rate of change was not uniform, with a rapid increase in mean BMI from 1995 to 2010. Beginning in 1965, the proportion of men with a BMI over 25 has been steadily increasing from one decade to the next, and was four times higher in 2010 than it was in 1965. The rate of increase per decade was twice as high from 2001 to 2010 than it was from 1995 to 2001. In 2010, only 70.8% of young men were of ideal weight.

CONCLUSION

Increase in obesity can be attributed to the social and economic changes brought about by the transformation of the country from a communist to a free-market economy in 1989. The challenges of the obesity epidemic for public health services and its impact on morbidity and life expectancy are also discussed.

Child maltreatment and household dysfunction: associations with pubertal development in a British birth cohort

BACKGROUND

We aimed to establish the association between adverse childhood experiences (maltreatment and household dysfunction) and pubertal maturation, which is associated with later health outcome(s).

METHODS

The 1958 British birth cohort (n = 17 638) includes all born in one week, March 1958, followed up to mid adulthood. Pubertal stage was rated by medical personnel at 11 and 16 years of age (y). Childhood maltreatment (neglect or abuse) and household dysfunction scores were constructed from information ascertained in childhood and at 45 y.

RESULTS

Childhood neglect, assessed at 7 y, was associated with late pubertal development on several markers after adjusting for early life circumstances: relative risk ratio (RRRadjusted) was 1.13 (95% CI: 1.06,1.21) and 1.06 (1.00,1.12) for late menarche and breast development (females) per unit increase in neglect score ranging 0-7, respectively; 1.14 (1.08,1.20) for late voice change and 1.07 (1.02,1.13) for pubic hair growth (males). The RRRadjusted for late pubic hair (females) and genitalia and facial hair (males) development was 1.04 (P = 0.052 to 0.085). Abuse score (0-3, for physical, sexual or psychological abuse) was associated in females with late menarche [RRRadjusted = 1.17 (1.01,1.36)] and in males with late pubic hair growth [RRRadjusted = 1.16 (1.01,1.34)] per unit increase, but not with other pubertal markers. Neither score (neglect or abuse) was associated with early puberty, but sexual abuse was associated with early [RRRadjusted = 1.86 (1.06,3.29)] as well as late menarche [RRRadjusted = 1.66 (1.02,2.71)] and witnessing abuse with early genitalia development [RRRadjusted = 1.57 (1.02,2.41)]. Household dysfunction score was not associated consistently with pubertal markers.

CONCLUSIONS

Cumulative neglect by 7 y was associated with delayed development of several pubertal markers. The underlying role of pubertal development in linking childhood neglect with future adult health warrants further consideration.

The timing of sexual maturation among boys and girls in eastern Poland, 1980-2000: a rural-urban comparison

The aim of this study was to determine secular changes in the sexual maturation of children and adolescents from Eastern regions of Poland between 1980 and 2000, with special attention paid to rural-urban differences. Our sample comprised 34,055 girls and 28,100 boys from 9 to 18 years of age. The age at which each gender reached each stage of sexual maturation was examined, along with menarcheal age in girls. An increase in the rate of sexual maturation was observed over the 20-year period of this study. Menarcheal age in girls decreased by 0.59 years. The length of sexual maturation decreased: from 6.58 years to 3.85 years in girls and from 5.84 years to 3.65 years in boys. A significantly faster rate of sexual maturation was observed between 1990 and 2000. Over the entire 20-year period, adolescents living in rural settings experienced a slower rate of sexual maturation than did their urban peers.

Pre-hypertension and hypertension in college students in Kuwait: a neglected issue

OBJECTIVE

To determine the proportion of pre-hypertension and hypertension in college students in Kuwait and their related risk factors.

MATERIALS AND METHODS

A total of 803, randomly selected students aged 17 to 23 years (346 male, 457 female) from different colleges in Kuwait, were included in the study between 2009 and 2010. Systolic and diastolic blood pressure measurements were taken by trained personnel. Pre-hypertension was defined as systolic pressure between 120 and 139 mm Hg or diastolic pressure between 80 and 89 mm Hg. Risk factor measurements that were determined, included smoking, body mass index (BMI), and family history of hypertension. Blood samples were collected and impaired glucose tolerance (IGT) and lipid profile levels were determined.

RESULTS

There were no hypotensive students. Normotensives constituted 53.5% (n = 430), pre-hypertensives formed 39.5% (n = 317), and hypertensive students comprised of 7% (n = 56). The overall proportions of hypertension and pre-hypertension were higher among male students (85.7 and 64.4%) than female students (14.3 and 35.6%), respectively. Hypertensive and pre-hypertensive students versus normotensive students had significantly higher levels of BMI-based obesity, smoking, glycated hemoglobin (HbA1c), and IGT. Also, hypertensive and pre-hypertensive, compared to normotensive students, had significantly higher proportions (21.4, 18.3, and 4.0%, respectively) of risky high-density lipoprotein (HDL) level (< 1 mg / dL), cholesterol (7.1, 3.8, and 1.4%, respectively), and triglycerides (TG) (17.9, 9.1, and 7.9%, respectively) where p was< 0.001, 0.016, and 0.051, respectively.

CONCLUSION

Hypertensive and pre-hypertensive students showed elevated levels of lipids and BMI-based obesity more than normotensive students. TG, HDL, HbA1c, and cholesterol appeared to influence pre-hypertension.

Pubertal timing and growth influences cardiometabolic risk factors in adult males and females

OBJECTIVE

Early pubertal onset in females is associated with increased risk for adult obesity and cardiovascular disease, but whether this relationship is independent of preceding childhood growth events is unclear. Furthermore, the association between male puberty and adult disease remains unknown. To clarify the link between puberty and adult health, we evaluated the relationship between pubertal timing and risk factors for type 2 diabetes and cardiovascular disease in both males and females from a large, prospective, and randomly ascertained birth cohort from Northern Finland.

RESEARCH DESIGN AND METHODS

Pubertal timing was estimated based on pubertal height growth in 5,058 subjects (2,417 males and 2,641 females), and the relationship between puberty and body weight, glucose and lipid homeostasis, and blood pressure at age 31 years was evaluated with linear regression modeling.

RESULTS

Earlier pubertal timing associated with higher adult BMI, fasting insulin, diastolic blood pressure, and decreased HDL cholesterol in both sexes (P < 0.002) and with higher total serum cholesterol, LDL cholesterol, and triglycerides in males. The association with BMI and diastolic blood pressure remained statistically significant in both sexes, as did the association with insulin levels and HDL cholesterol concentrations in males after adjusting for covariates reflecting both fetal and childhood growth including childhood BMI.

CONCLUSIONS

We demonstrate independent association between earlier pubertal timing and adult metabolic syndrome-related derangements both in males and females. The connection emphasizes that the mechanisms advancing puberty may also contribute to adult metabolic disorders.

Perinatal environmental exposures affect mammary development, function, and cancer risk in adulthood

Puberty is an important transition that enables reproduction of mammalian species. Precocious puberty, specifically early thelarche (the appearance of breast "buds"), in girls of multiple ethnic backgrounds is a major health problem in the United States and other countries. The cause for a continued decrease in the age of breast development in girls is unknown, but environmental factors likely play a major role. Laboratory and epidemiological studies have identified several individual environmental factors that affect breast development, but further progress is needed. Current research needs include increased attention to and recording of prenatal and neonatal environmental exposures, testing of marketed chemicals for effects on the mammary gland, and understanding of the mammary gland-specific mechanisms that are altered by chemicals. Such research is required to halt the increasing trend toward puberty at earlier ages.

Association of the timing of puberty with a chromosome 2 locus

CONTEXT

Twin studies indicate that the timing of pubertal onset is under strong genetic control. However, genes controlling pubertal timing in the general population have not yet been identified.

OBJECTIVE

To facilitate the identification of genes influencing the timing of pubertal growth and maturation, we conducted linkage mapping of constitutional delay of growth and puberty (CDGP), an extreme variant of normal pubertal timing, in extended families.

PARTICIPANTS AND METHODS

Fifty-two families multiply affected with CDGP were genotyped with 383 multiallelic markers. CDGP was defined based on growth charts (the age at onset of growth spurt, peak height velocity, or attaining adult height taking place at least 1.5 sd later than average). Chromosomal regions cosegregating with CDGP were identified with parametric affected-only linkage analysis using CDGP as a dichotomized trait.

RESULTS

The genome-wide scan detected linkage of CDGP to a region on chromosome 2p13-2q13. The two-point heterogeneity LOD (HLOD) score was 1.62 (alpha = 0.27), and the corresponding multipoint HLOD was 2.54 (alpha = 0.31). Fine-mapping the region at 1 cM resolution increased the multipoint HLOD score to 4.44 (alpha = 0.41). The linkage became weaker if family members diagnosed with CDGP without growth data were also included in the analyses.

CONCLUSIONS

The pericentromeric region of chromosome 2 harbors a gene predisposing to pubertal delay in multiply affected pedigrees. Our data suggest that this locus may be a component of the internal clock controlling the timing of the onset of puberty.