Fatness and Fitness With Cardiometabolic Risk Factors in Adolescents

Reciprocal Longitudinal Relationship Between Fitness, Fatness, and Metabolic Syndrome in Brazilian Children and Adolescents: A 3-Year Longitudinal Study

PURPOSE

To verify the reciprocal longitudinal relationships between cardiorespiratory fitness (CRF), percentage body fat (%body fat), and metabolic syndrome in Brazilian primary school students.

METHOD

This longitudinal study involved 420 children and adolescents followed for 3 years (2011-2014). The continuous Metabolic Syndrome (cMetSyn) score was calculated by summing adjusted z scores of glucose, systolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, and waist circumference. The CRF was assessed using running/walking tests, and %body fat was assessed through sex-specific 2-site skinfold thickness. Cross-lagged panel models were used to analyze longitudinal reciprocal relationships between CRF and %body fat with cMetSyn.

RESULTS

Results indicated that 2011 %body fat significantly predicted both 2014 CRF scores and 2014 cMetSyn scores (P < .001); however, 2011 CRF only predicted 2014 %body fat (P < .001) but not 2014 cMetSyn (P = .103). Furthermore, 2011 cMetSyn predicted 2014 %body fat (P = .002). The model explained 36%, 48%, and 37% of the variance in 2014 CRF, %body fat, and cMetSyn, respectively.

CONCLUSION

The results suggest a reciprocal inverse relationship between %body fat and metabolic syndrome risk and that %body fat may play a more important role in the risk of developing metabolic syndrome compared with CRF.

Prevalence and Associated Factors of Physical Activity Among Older Adults Living in Nursing Homes: A Cross-Sectional Study

In many countries, the physical activity level of nursing home residents is low, and the amount of time spent on such behavior has not been quantified in China. In the current study, pedometers were used to measure the physical activity levels of 349 nursing home residents. Daily steps for residents ranged from 5 to 16,773 steps per day, with a median of 1,608 steps per day. Three hundred (85.96%) residents were sedentary, 16 (4.6%) were low active, and 33 (9.5%) were physically active. Factors such as the living conditions of the nursing home, younger age, lower body mass index, higher educational level, marriage, higher pension, and greater family support all led to a higher physical activity level among residents. Regarding sedentary level, male residents were more active than female residents. The physical activity level of nursing home residents in China is lower than the current World Health Organization standard. [Journal of Gerontological Nursing, 46(10), 19-26.].

Decreased Physical Working Capacity in Adolescents With Nonalcoholic Fatty Liver Disease Associates With Reduced Iron Availability

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is common and related to obesity and insulin resistance. Iron metabolism is impaired in obese individuals and iron deficiency has been associated with physical inactivity. We investigated whether iron bioavailability is reduced in patients with NAFLD and contributes to reduced cardiorespiratory fitness.

METHODS

We collected information on weight-adjusted, submaximal physical work capacity (PWC), ultrasound-determined hepatic steatosis, iron indices, and hematologic and metabolic parameters from 390 female and 458 male participants of the Raine Study-a longitudinal study of disease development in 2868 children in Western Australia. X² and linear regression analyses were used to compare characteristics of study participants according to NAFLD status at age 17 years.

RESULTS

Fourteen percent of the cohort had NAFLD. PWC was significantly reduced in adolescents with NAFLD compared to adolescents without NAFLD (reduction of 0.17 W/kg, P = .0003, adjusted for sex and body mass index [BMI]). Iron bioavailability (assessed by mean corpuscular volume [MCV], mean corpuscular haemoglobin [MCH], transferrin saturation, and serum levels of iron) was inversely correlated with BMI in adolescents with NAFLD (P ≤ .01 for all, adjusted for sex) but not in adolescents without NAFLD (P > .30). MCV and MCH correlated with PWC (MCV, P = .002 for female and P = .0003 male participants; MCH, P = .004 for female and P = .01 for male participants), irrespective of NAFLD status. Reduced PWC was associated with lower transferrin saturation in adolescents with NAFLD (reduction of 0.012 W/kg per unit decrease in transferrin saturation, P = .007) but not in adolescents without NAFLD (reduction of 0.001 W/kg, P = .40), adjusted for sex. This association was independent of MCV or MCH.

CONCLUSIONS

In a well-defined cohort of adolescents, we found NAFLD to be associated with decreased cardiorespiratory fitness, independent of BMI. The relationship between transferrin saturation and PWC in adolescents with NAFLD indicates that functional iron deficiency might contribute to reductions in cardiorespiratory fitness.

Lower than average HDL cholesterol efflux capacity in Lithuanian population

Background

The aim of our study was to evaluate high-density lipoprotein cholesterol (HDL-C) efflux capacity in healthy controls and patients with severe dyslipidemia. Evaluation of HDL function may be beneficial for better understanding of cardiovascular diseases, as well as for taking actions to minimize residual cardiovascular risk.

Methods

During 2016–2017 a total of 93 participants – 48 (51.6%) women and 45 (48.4%) men – were included in this cross-sectional study. Data of 45 (48.4%) participants with severe dyslipidemia (SD) and 48 (51.6%) controls without dyslipidemia was used for statistical analysis. Total lipid panel, concentration of lipoprotein (a) and apolipoproteins were measured, data about cardiovascular risk factors were collected and detailed evaluation of HDL-C quality was performed for all patients.

Results

Increased HDL-C concentration was associated with higher ApoA1 (r = 0.866 in controls, r = 0.63 in SD group), ApoA2 (r = 0.41 in controls, r = 0.418 in SD group) and LDL-C concentrations (r = − 0.412 in SD group), lower ApoE (r = − 0.314 in SD group) and TG concentrations (r = − 0.38 in controls, r = − 0.608 in SD group), lower ApoB/ApoA1 ratio (r = − 0.567 in control group), below average HDL-C efflux capacity (r = − 0.335 in SD group), lower BMI (r = − 0.327 in controls, r = − 0.531 in SD group) and abdominal circumference (r = − 0.309 in women with SD). Below-average HDL-C efflux capacity was found in 67.7% (N = 63) of participants. It was more often found among patients with normal weight or BMI 30–31 kg/m2. HDL-C efflux capacity was inversely associated with HDL-C concentration (r = − 0.228).

Conclusion

Abnormal HDL function may be associated with residual cardiovascular risk in Lithuanian population.

The influence of cardiorespiratory fitness on clustered cardiovascular disease risk factors and the mediator role of body mass index in youth: The UP&DOWN Study

BACKGROUND

The combined effect of cardiorespiratory fitness (CRF) and body mass index (BMI) on cardiovascular disease (CVD) risk in young people remains to be fully determined. We examined the individual and combined associations of CRF and BMI with clustered CVD risk factors, and the mediator role of BMI in the association between CRF and clustered CVD risk factors in children and adolescents.

METHODS

237 children (111 girls) and 260 adolescents (120 girls) were included in this cross-sectional study. Height and weight were assessed and BMI was calculated. A CVD risk factor index (CVDRF-I) was computed from: waist circumference, systolic blood pressure, triglycerides, high-density lipoprotein cholesterol and glucose. CRF was assessed using the 20-m shuttle run test. Regression analysis, analysis of covariance and mediation analysis (Baron and Kenny procedures) were used to test the independent and combined effect of CRF and BMI on CVDRF-I, and to test mediation hypothesis, respectively.

RESULTS

CRF was negatively associated with CVDRF-I (all P < 0.05); however, after adjusting for BMI the associations were no longer significant in children and adolescents of both sex groups. Contrary, the association between BMI and CVDRF-I was independent of CRF (all P < 0.001). The effect of CRF on CVDRF-I was mediated by BMI. The percentage of the total effect of CRF on CVDRF-I mediated by BMI for boys and girls children and boys and girls adolescents were 79.5%, 100%, 81.2% and 55.7%, respectively.

CONCLUSIONS

BMI is an independent predictor of CVDRF-I and a mediator of the association between CRF and CVDRF-I in children and adolescents. These results help to clarify the associations between CRF, weight status and cardiovascular health, suggesting that future CVD health would benefit from maintaining an optimal weight status.