Cardiovascular reactivity and cardiometabolic risk in adolescents.

BACKGROUND: Cardiovascular reactivity has been examined as a risk marker or factor in the pathogenesis of hypertension or cardiovascular disease, but few have examined the relationship with the metabolic syndrome. PURPOSE: We examined whether cardiovascular reactivity to laboratory stress is associated with individual cardiometabolic risk factors and their co-occurrence. A significant positive relationship was hypothesized for both individual and clustered risk factors in their cross-sectional associations with reactivity to multiple stressors. METHODS: A sample of 144, 15-17-year-old adolescents (74 % boys) largely from ethnic minority groups (54 % Hispanic White, 26 % Black) were identified at annual blood pressure (BP) screening (39 % with elevated BP) at high schools in Miami, Florida, USA. Participants completed the evaluated speaking, mirror star tracing, and cold pressor tasks, as well as cardiometabolic risk factor blood sampling. Participants were classified into metabolic syndrome criterion groups (0, 1, 2, or ≥3 criteria) based on American Heart Association adult criteria. RESULTS: Multiple regression analyses with individual metabolic syndrome variables demonstrated that diastolic (D)BP reactivity during the mirror star tracing task accounted for 1.3 %, 3.8 %, and 5.1 % of the respective variances in casual systolic BP, waist circumference, and triglycerides (ps < 0.05). In multinomial logistic regression models, increased DBP reactivity during mirror star tracing and cold pressor tasks, and decreased HR reactivity during the cold pressor, were associated with greater likelihood of risk factor co-occurrence (ranging from 8.3 % to 15.8 %). CONCLUSIONS: Findings indicate that autonomic reactivity to the mirror star tracing and cold pressor tasks, but not the evaluated speaking task, is associated with risk factor co-occurrence, and reactivity may be a clinical prognosticator of cardiometabolic disease risk.

Cardiometabolic risk in adolescents: associations with physical activity, fitness, and sleep.

BACKGROUND: Physical activity and fitness are independently associated with cardiometabolic dysfunction, and short sleep duration is an emerging marker of obesity. Few have examined interrelations among these factors in a comprehensive risk model. PURPOSE: Investigate the influence of behavioral and lifestyle risk factors on the metabolic syndrome and inflammation. METHODS: A sample of 367 15-17-year-olds (73 % boys) from ethnic minority groups (45.8 % Hispanic, 30.8 % Black), most with elevated blood pressure (72 %), underwent aerobic fitness testing, blood sampling, and completed behavioral questionnaires. RESULTS: Structural model results are consistent with the notion that short sleep duration, poor sleep quality and fatigue, and decreased physical activity are associated with increased risk of metabolic syndrome and inflammation possibly via effects on reduced cardiorespiratory fitness. CONCLUSIONS: The combination of negative lifestyle and behavioral factors of physical inactivity, sleep loss, and poor fitness has serious implications for cardiovascular health complications in at-risk youth.

The prospective contribution of hostility characteristics to high fasting glucose levels: the moderating role of marital status.

OBJECTIVE: To assess whether psychological constructs of hostility, anger, type A behavior pattern, and depressive symptom severity 1) were associated with concurrent and prospective fasting glucose levels and 2) whether this association was moderated by marital status. RESEARCH DESIGN AND METHODS: Participants were 485 healthy men ([mean +/- SD] age 59 +/- 7 years) without a history of heart disease, diabetes, or taking related medications in the Veterans Affairs Normative Aging Study. Their fasting glucose levels between 1986 and 1995 were examined. Hierarchical linear regressions were conducted to investigate whether hostility, anger, type A behavior, and depressive symptoms were associated with concurrent fasting glucose levels as well as fasting glucose 9 years later, controlling for standard sociodemographic and biomedical covariates, including baseline fasting glucose, age, education, marital status, BMI, total cholesterol, and systolic blood pressure. RESULTS: Although none of the psychological variables were associated with concurrent fasting glucose, Cook-Medley hostility (beta = 0.105), anger (beta = 0.091), and type A behavior (beta = 0.152) each were associated with prospective fasting glucose 9 years later, controlling for standard covariates. Depressive symptom severity was not associated with either concurrent or follow-up glucose levels. Further analysis showed that marital status moderated the effects of these characteristics on follow-up fasting glucose such that hostility, anger, and type A behavior were significant only among those who were not married (beta = 0.348, 0.444, 0.439, respectively; all P <0.001). CONCLUSIONS: Hostility, anger, and type A behavior appear to be independent risk factors for impaired glucose metabolism among unmarried older men.