Prenatal Testosterone Associates With Blood Pressure in Young Adults: A Prospective Cohort Study.

[Figure: see text].

The historic oil price fluctuation during the Covid-19 pandemic: What are the causes?

On 20 April 2020, the West Texas Intermediate (WTI) crude oil price dropped to negative levels for the first time in history. This study examines the factors underlying the historic oil price fluctuation during the Covid-19 pandemic. The autoregressive distributed lag (ARDL) bounds testing approach incorporating a structural break is applied to the daily series from 17 January to 14 September 2020 to analyze long-run relationships and short-run dynamics. The results reveal that increases in Covid-19 pandemic cases, US economic policy uncertainty, and expected stock market volatility contributed to the fall in the WTI crude oil price, whereas the fall in the global stock markets appears to significantly reduce the fall. Furthermore, the Russia-Saudi Arabia oil price war and speculation on oil futures are shown to play a critical part in the collapse of the oil markets. The findings are consistent with our expectations. Although it is reasonable to assume that the solution to this oil crisis is a pick-up in global oil demand, which will occur only when the novel coronavirus is defeated, this study proposes policy recommendations to cope with the current oil price crash.

Age at menarche and childhood body mass index as predictors of cardio-metabolic risk in young adulthood: A prospective cohort study.

OBJECTIVE: This study aimed to examine the association between age at menarche and a range of cardiovascular disease (CVD) risk factors at 17 and 20 years of age, and whether this was influenced by childhood body mass index (BMI). METHODS: Of the 1413 girls born in the Western Australian Pregnancy Cohort (Raine) Study, 846 had age at menarche recorded. Subsequently 557 underwent metabolic assessment at 17 years and 541 at 20 years. Associations between age at menarche and cardiovascular risk factors, and being in a high-risk metabolic cluster at 17 and 20 years, or having the metabolic syndrome at 20 years, were investigated by linear mixed effects and logistic regressions, respectively. RESULTS: Each year later of onset of menarche was associated with a 0.75 kg/m2 reduction in BMI (coefficient -0.75 [95%CI -1.06, -0.44]), and an approximate 30% reduction in the odds of being in the high-risk metabolic cluster at 17 years (OR = 0.73 [95%CI 0.57, 0.94]) and 20 years of age (OR = 0.68 [95%CI 0.52, 0.87]), and a 40% reduction in the odds of having the metabolic syndrome at 20 years (OR = 0.60 [95% CI 0.41, 0.88]). These data show earlier age at menarche was associated with increased BMI and odds of being in the high-risk metabolic cluster at 17 and 20 years, and increased odds of having the metabolic syndrome at 20 years. However, these associations were no longer statistically significant after adjustment for BMI at age 8 years. Current smoking, alcohol consumption, physical activity, socio-economic status, or hormonal contraceptives use did not affect these associations. CONCLUSIONS: Earlier age at menarche may be indicative of a higher risk profile for CVD in young adulthood. Our findings suggest that targeted interventions to reduce BMI in girls who experience menarche at younger age may reduce CVD risk in the future.

Hypothalamic-pituitary-adrenal axis activity under resting conditions and cardiovascular risk factors in adolescents.

BACKGROUND: Activation of the hypothalamic-pituitary-adrenal (HPA) axis has been associated with higher levels of cardiovascular (CVD) risk factors in adults. This study aimed to assess the relation between measures of HPA axis activity under resting conditions and CVD risk factors in a general population of adolescents at 17 years. METHODS: A total of 1134 adolescents from the Western Australian Pregnancy Cohort (Raine) Study had phenotypic and socio-demographic data. The associations between HPA axis measures (plasma ACTH, total cortisol, calculated free cortisol, corticosteroid binding globulin (CBG), and salivary cortisol) and a range of cardiovascular risk factors were examined using multivariable linear regression models, with adjustment for gender, adiposity, birth weight, gestational age, and socio-behavioural factors. RESULTS: Plasma total cortisol was positively associated with systolic blood pressure (SBP) (p=0.011), total cholesterol, HDL-cholesterol, and triglycerides (all p<0.001), and hs-CRP (p=0.047). Salivary cortisol was associated positively with HDL-C (p=0.033) and negatively with LDL-cholesterol (p=0.016); plasma calculated free cortisol was positively associated with triglycerides (p=0.006); plasma CBG was positively associated with total cholesterol and HDL-cholesterol (both p<0.001), LDL-cholesterol (p=0.022), and hs-CRP (p=0.001). After correction for multiple comparisons, significant associations remained for total cortisol with total cholesterol, HDL-C, and triglycerides; for calculated free cortisol with triglycerides; and for CBG with HDL-C, total cholesterol, and hs-CRP. Plasma ACTH was not associated with any cardiovascular risk factor. There was no association between BMI and any measure of HPA axis activity. CONCLUSION: In an adolescent population, HPA axis measures under resting conditions are associated with a range of CVD risk factors. Clarification of the mechanisms underlying these associations in adolescence would be an important step in understanding the evolution of adult CVD.

Gender and the active smoking and high-sensitivity C-reactive protein relation in late adolescence.

C-reactive protein (CRP), smoking, and oral contraceptive (OC) use are associated with CVD risk in adults. This study examines the effect of smoking on high-sensitivity CRP (hs-CRP) levels, and the interactive effects of sex and OC use on this relationship in an adolescent cohort. A total of 1,050 adolescents (mean age 17 ± 0.25 years) from the Western Australian Pregnancy Cohort (Raine) Study had anthropometric, lifestyle, and metabolic measures recorded. The association between smoking status and log-transformed hs-CRP was analyzed using multivariable Tobit linear regression models, with adjustment for adiposity, lifestyle, and early-life confounders. A three-level variable (girls not using OCs, girls using OCs, and boys) was employed to assess the interactive effects of sex, OC use, and smoking. Smoking associated with higher hs-CRP levels in girls not using OCs (b = 0.571; P = 0.001), but not in girls using OCs (b = -0.117; P = 0.598) or in boys (b = 0.183; P = 0.2). OC use in nonsmoking girls was the strongest factor associated with higher hs-CRP levels (b = 1.189; P < 0.001). This study has demonstrated a more robust effect of smoking on hs-CRP levels in girls not using OCs compared with boys. The findings may explain why CVD risk conferred by smoking is higher in women than in men.

Gender difference in the relationship between passive smoking exposure and HDL-cholesterol levels in late adolescence.

BACKGROUND: High-density lipoprotein-cholesterol (HDL-C) levels are influenced by gender and by genetic and environmental factors. We aimed to assess the impact of passive smoking exposure since birth on HDL-C levels of nonsmoking adolescents at age 17 years and to determine whether there was a gender difference in the relationship between smoking exposure and HDL-C. METHODS: A total of 804 nonsmoking adolescents with biochemical, anthropometric, and lifestyle data from a cohort of 1754 adolescents (mean age, 17 ± 0.25 y) of the Western Australian Pregnancy Cohort (Raine) Study had data of maternal smoking during pregnancy and smoking exposure in the household over 17 years. HDL-C was analyzed using multivariable linear regression, with adjustment for early-life, adiposity, and current lifestyle confounders. RESULTS: HDL-C levels were significantly lower in girls exposed to passive smoking compared to those not exposed (regression coefficient b = -0.09 [95% confidence interval, -0.15, -0.03]); this was not observed in boys (b = 0.02 [95% confidence interval, -0.04, 0.08]), with a significant sex interaction P = .009. The effects of passive smoking in girls persisted after adjusting for oral contraceptive use. CONCLUSIONS: This study has shown a gender difference in the relationship between passive smoking exposure since birth and HDL-C in late adolescence. Exposure to passive smoking in girls could have adverse consequences on their risk of cardiovascular disease in adulthood. These findings reinforce the need for future public health measures to reduce children's exposure to passive smoking.

Oral contraceptive use in girls and alcohol consumption in boys are associated with increased blood pressure in late adolescence.

AIMS: Lifestyle behaviours established during adolescence may adversely affect blood pressure (BP) and contribute to gender differences in cardiovascular risk in adulthood. We aimed to assess the association of health behaviours with BP in adolescents, using data from the Western Australian Pregnancy (Raine) Study. METHODS: Cross-sectional analysis on 1248 Raine Study adolescents aged 17 years, to examine associations between lifestyle factors and BP. RESULTS: Boys had 8.97 mmHg higher systolic BP, as compared with girls. The 30% of girls using oral contraceptives (OC) had 3.27 and 1.74 mmHg higher systolic and diastolic BP, respectively, compared with non-users. Alcohol consumption in boys, increasing body mass index (BMI) and the sodium-potassium ratio were associated with systolic BP. We found a continuous relationship between BMI and systolic BP in both genders; however, the gradient of this relationship was significantly steeper in boys, compared with girls not taking OC. In boys, systolic BP was 5.7 mmHg greater in alcohol consumers who were in the upper quartile of BMI and the urinary sodium-potassium ratio compared with teetotallers in the lowest quartile. In girls, systolic BP was 5.5 mmHg higher in those taking OC, in the highest BMI and urinary sodium-potassium ratio quartile as compared to those not taking the OC pill and in the lowest quartile. CONCLUSION: In addition to gender-related differences in the effects of adiposity on BP, we found lifestyle-related health behaviours such as high salt intake for both sexes, consumption of alcohol in boys, and OC use in girls were important factors associated with BP measurements in late adolescence. This suggests that gender-specific behavioural modification in adolescence may prevent adult hypertension.

Sex dimorphism in the relation between early adiposity and cardiometabolic risk in adolescents.

CONTEXT: Birth weight and childhood adiposity are associated with subsequent cardiovascular risk. OBJECTIVE: We investigated the associations between metabolic clusters in young adults with body fat distribution from early childhood, focusing on sex differences. DESIGN, SETTING, AND PATIENTS: A total of 1053 17 yr olds from an Australian birth cohort had measures of anthropometry, blood pressure, and fasting insulin, glucose, and lipids. MAIN OUTCOME MEASURES: Two-step cluster analysis identified 17 yr olds at high metabolic risk. The two risk groups were compared by sex with regard to birth weight and serial anthropometry, including skinfold thickness from nine time-points. RESULTS: The "high-risk" metabolic cluster at age 17 yr included 16% of males and 19% of females. Compared to the "low-risk" group, the high-risk cluster participants had greater waist circumference, triglycerides, insulin, and systolic blood pressure and lower high-density lipoprotein-cholesterol (all P <0.0001). There was a significant birth weight by sex interaction upon the metabolic cluster outcome (P = 0.011). Compared to their low-risk counterparts, females in the high-risk cluster at 17 yr were heavier from birth (odds ratio, 1.8; 95% confidence interval, 1.0, 3.2) (P = 0.034), with consistently higher body mass index and skinfold thickness thereafter. In contrast, there was no statistical difference in birth weight between high- and low-risk males (odds ratio, 0.62; 95% confidence interval, 0.38, 1.02). CONCLUSIONS: These data show sexual dimorphism in effects of early life body mass index and fat distribution upon cardiometabolic risk factors. Females in a contemporary population are particularly prone to increased risk when born heavier. This has implications for targeted prevention of obesity and metabolic diseases with increasing maternal obesity and gestational diabetes.