Pulmonary function changes in older adults with and without metabolic syndrome.

The low-grade inflammation associated with metabolic syndrome (MS) triggers functional and structural alterations in several organs. Whereas lung function impairment is well reported for older adult population, the effect of MS on functional and immunological responses in the lungs remains unclear. In this cross-sectional study we determined whether MS alters pulmonary function, and immunological responses in older adults with MS. The study sample consisted of older adults with MS (68 ± 3 years old; n = 77) and without MS (67 ± 3 years old; n = 77). Impulse oscillometry was used to evaluate airway and tissue resistance, and reactance. Biomarkers of inflammation and fibrosis were assessed in the blood and in breath condensate. The total resistance of the respiratory system (R5Hz; p < 0.009), and the resistance of the proximal (R20Hz; p < 0.001) and distal (R5Hz-R20Hz; p < 0.004) airways were higher in MS individuals compared to those without MS. Pro-inflammatory (leptin, IL-1beta, IL-8, p < 0.001; TNF-alpha, p < 0.04) and anti-inflammatory cytokines (adiponectin, IL-1ra, IL-10, p < 0.001), anti-fibrotic (relaxin 1, relaxin 3, Klotho, p < 0.001) and pro-fibrotic (VEGF, p < 0.001) factors were increased in sera and in breath condensate individuals with MS. The results show that MS adversely affect lung mechanics, function, and immunological response in older adults. The data offer a metabolic basis for the inflammaging of the lungs and suggest the lungs as a potential therapeutic target for controlling the immune response and delaying the onset of impaired lung function in older adults with MS.

Self-initiated physical activity is associated with high sensitivity C-reactive protein: A longitudinal study in 5,030 adults.

BACKGROUND AND AIMS: Structured regular exercise programs decrease high-sensitivity C-reactive protein (hsCRP), a marker of low-grade inflammation in adults. Longitudinal effects of self-initiated physical activity levels (PAL) on hsCRP are less clear. This study evaluated the association of longitudinal changes in hsCRP in relation to modifications in PAL, over time, in a large sample of adults. METHODS: Participants included 5030 adults, 4045 (80%) males, undergoing routine health screening examinations. Elevated level of hsCRP was defined as ≥3 mg/L. Self-reported PAL, height, weight, blood pressure and blood samples were collected at baseline and after a median of 2.9 years (P25th 1.97 and P75th 4.37 yrs). Participants were stratified according to their PAL at baseline and follow-up as: i) persistently physically inactive; ii) became physically inactive; iii) became physically active; iv) persistently physically active (active both at baseline and follow-up). RESULTS: Persistently physically active participants had lower odds of having higher hsCRP (OR = 0.35 [95% CI: 0.25 to 0.48]). The maintenance of high PAL was associated with lower hsCRP in both sexes (men: OR = 0.44 [0.30 to 0.65] and women: OR = 0.35 [0.16 to 0.76]). Participants with overweight/obesity (OR = 0.43 [95% CI: 0.29 to 0.63]) and smokers (OR = 0.123 [95% CI: 0.03 to 0.60]) who were persistently active had lower odds of having higher hsCRP compared to physically inactive peers. CONCLUSIONS: Self-initiated PAL was longitudinally associated with hsCRP in adults. The data suggest that the initiation or maintenance of PA attenuates the low-grade inflammatory state, independent of sex, body weight and smoking status.

Physical activity levels and hepatic steatosis: A longitudinal follow-up study in adults.

BACKGROUND AND AIM: This study aimed to evaluate the impact of physical activity (PA) on the course of hepatic steatosis (HS) in adults. METHODS: Hepatic steatosis status (ultrasonography) and PA levels were evaluated in 5860 subjects at baseline and after approximately 2.5 years (range: 19-50 months). At follow up, possible exposures to different PA levels were those who remained inactive, became inactive, became active, and remained active. After follow up, subjects were then classified according to the four possible states (outcomes): "remained without HS," "developed HS" (subjects without HS at baseline), "remained with HS," or "reverted HS." RESULTS: After multivariate adjustments, individuals without HS that became or remained physically active were less likely to develop HS compared with those who remained physically inactive (odds ratio = 0.75, P = 0.04 and 0.75, P = 0.03, respectively). Among those with HS at baseline, becoming and remaining physically active beneficially improved the HS status (odds ratio = 0.64, P = 0.01 and 0.66, P = 0.01, respectively). However, the significance was lost when adjusted for changes in body mass index. CONCLUSION: Higher levels of PA were associated with prevention and treatment of HS, with evidence of effect mediation by changes in body mass index.

Association between resting heart rate and cardiovascular risk factors in adolescents.

This cross-sectional study was performed in 2011 and included 4619 Brazilian adolescents (14-19 years old) to analyze the association between elevated resting heart rate (RHR) and cardiovascular risk factors in boys and girls. RHR and blood pressure were measured using an oscillometric monitor. Overweight was assessed by body mass index and abdominal obesity by waist circumference. Physical activity levels and sedentary behaviors were obtained using a questionnaire. The effect of clustering of cardiovascular risk factors on RHR was analyzed. For boys, abdominal obesity (b = 0.106, p = 0.003), high sedentary behavior (b = 0.099, b < 0.001), physical inactivity (b = 0.049, p = 0.034), and high blood pressure (b = 0.160, p < 0.001) were associated with RHR, whereas for girls, only high blood pressure was associated with RHR (b = 0.259, p < 0.001), after adjustment for age, period of the day, and other cardiovascular risk factors. Boys with five risk factors presented significantly higher (p < 0.05) RHR values (82.5 ± 13.4 beats min(-1)) than those for boys without any cardiovascular risk factors (68.8 ± 10.4 beats min(-1)). The girls with five risk factors presented a mean RHR value of 89.8 ± 9.9 beats min(-1) that was higher (p < 0.05) than that for girls who had no risk factors (79.6 ± 10.9 beats min(-1)). CONCLUSIONS: Our study demonstrated that while RHR was associated with cardiovascular risk factors in both sexes, the clustering of risk factors amplified the elevation of RHR in a gender-dependent fashion. WHAT IS KNOWN: • Resting heart rate is a marker of cardiovascular disease and mortality in adults and associated with risk factor such as higher levels of blood pressure, triglycerides, glucose, and obesity in children and adolescents. WHAT IS NEW: • The data from the current study suggest that the risk factor clustering is associated with elevated resting heart rate in adolescents and that the clustering of risk factors amplifies the elevation of resting heart rate in a gender-dependent fashion.

Effect of aerobic exercise on hunger feelings and satiety regulating hormones in obese teenage girls.

Exercise is implicated in modifying subsequent energy intake (EI) through alterations in hunger and/or satiety hormones. Our aim was to examine the effects of aerobic exercise on hunger, satiety regulatory peptides, and EI in obese adolescents. Nine obese girls (age: 13-18 years old, BMI: 33.74 ± 4.04 kg/m2) participated in this randomized controlled crossover study. Each participant randomly underwent 2 experimental protocols: control (seated for 150 min) and exercise (exercised for 30 min on a treadmill performed at ventilatory threshold [VT] intensity and then remained seated for 120 min). Leptin, peptide YY(3-36) (PYY(3-36)), and subjective hunger were measured at baseline as well as 30 min and 150 min, followed by 24-hr EI measurement. Exercise session resulted in an acute increase in PYY(3-36) (p < .01) without changes in leptin and/or hunger scores. The control session increased hunger scores (p < .01) and decreased circulating leptin levels (p = .03). There was a strong effect size for carbohydrate intake (d = 2.14) and a modest effect size for protein intake (d = 0.61) after the exercise compared with the control session. Exercise performed at VT intensity in this study appears to provoke a state of transient anorexia in obese girls. These changes may be linked to an increase in circulating PYY3-36 and maintenance of leptin levels.

Does exercise intensity affect blood pressure and heart rate in obese adolescents? A 6-month multidisciplinary randomized intervention study.

BACKGROUND: Aerobic exercise improves cardiovascular health in general, but whether the impact varies with exercise intensity is not clear. OBJECTIVE: The aim of the current study was to compare the effects of a high-intensity aerobic exercise training (HIT) vs. a low-intensity aerobic exercise training (LIT) on blood pressure (BP), heart rate (HR) and heart rate variability (HRV) in obese adolescents. METHODS: Forty-three (13-18 years) Tanner stage (III-IV) matched obese adolescents were studied in a randomized trial of either HIT (corresponding to the ventilatory threshold I; n = 20) or LIT (corresponding to 20% below the ventilatory threshold I; n = 23) programme for a period of 6 months. All participants also received a multidisciplinary therapy that included nutritional, psychological and clinical counselling. Both HIT and LIT sessions were isocaloric, with energy expenditure set at 350 kcal. BP, HR and HRV were measured along with markers of body adiposity and insulin resistance before and after the respective interventions. RESULTS: The participants in both groups had similar physical and clinical characteristics. After the 6-month intervention, systolic, diastolic and mean BP decreased (P < 0.05, for all) similarly in both groups, whereas waist circumference, HR and HRV showed beneficial changes only in the HIT group (P < 0.05). CONCLUSION: Aerobic exercise training set at a high intensity compared with the low intensity appears to have additional benefits on abdominal obesity and cardiovascular health in that it enhances the parasympathetic and autonomic modulation of the heart in obese adolescents.