High-intensity interval training induced PGC-1∝ and AdipoR1 gene expressions and improved insulin sensitivity in obese individuals

INTRODUCTION

High-intensity interval training (HIIT) has been found to improve cardiometabolic health outcome as compared to moderate-intensity continuous exercise. However, there is still limited data on the benefits of HIIT on the expression of regulatory proteins that are linked to skeletal muscle metabolism and insulin sensitivity in obese adults. This study investigated the effects of HIIT intervention on expressions of peroxisome proliferatoractivated receptor-γ coactivator 1-∝ (PGC-1∝) and adiponectin receptor-1 (AdipoR1), insulin sensitivity (HOMAIR index), and body composition in overweight/obese individuals.

METHODS

Fifty overweight/obese individuals aged 22-29 years were assigned to either no-exercise control (n=25) or HIIT (n=25) group. The HIIT group underwent a 12-week intervention, three days/week, with intensity of 65-80% of age-based maximum heart rate. Anthropometric measurements, homeostatic model of insulin resistance (HOMA-IR) and gene expression analysis were conducted at baseline and post intervention.

RESULTS

Significant time-by-group interactions (p<0.001) were found for body weight, BMI, waist circumference and body fat percentage. The HIIT group had lower body weight (2.3%, p<0.001), BMI (2.7%, p<0.001), waist circumference (2.4%, p<0.001) and body fat percentage (4.3%, p<0.001) post intervention. Compared to baseline, expressions of PGC-1∝ and AdipoR1 were increased by approximately three-fold (p=0.019) and two-fold (p=0.003) respectively, along with improved insulin sensitivity (33%, p=0.019) in the HIIT group.

CONCLUSION

Findings suggest that HIIT possibly improved insulin sensitivity through modulation of PGC-1∝ and AdipoR1. This study also showed that improved metabolic responses can occur despite modest reduction in body weight in overweight/obese individuals undergoing HIIT intervention.

Characteristics associated with the consumption of malted drinks among Malaysian primary school children: findings from the MyBreakfast study

BACKGROUND

The consumption of beverages contributes to diet quality and overall nutrition. Studies on malted drinks, one of the widely consumed beverage choices among children in Asia, however, have received limited attention. This study aimed to examine the prevalence of malted drink consumption and explored associations of sociodemographic characteristics, nutrient intakes, weight status and physical activity levels with malted drink consumption among primary school children in Malaysia.

METHODS

Data for this analysis were from the MyBreakfast Study, a national cross-sectional study conducted from April to October 2013 throughout all regions in Malaysia. A total of 2065 primary school children aged 6 to 12 years were included in the present analysis. Data on two days 24-h dietary recall or record, anthropometry, physical activity and screen time were recorded. Associations between malted drink consumption and related factors were examined using binary logistic regression, adjusting for region, area, gender, ethnicity and household income.

RESULTS

Among children aged 6 to 12 years, 73.5% reported consuming malted drinks for at least once per week. Consumption of malted drinks was significantly associated with region (χ(2) = 45.64, p < 0.001), gender (χ(2) = 4.41, p = 0.036) and ethnicity (χ(2) = 13.74, p = 0.008). Malted drink consumers had similar total energy intake but higher micronutrient intakes compared to non-consumers. High physical activity level (OR = 1.77, 95% CI = 1.06, 2.99) and lower screen time during weekends (OR = 0.93, 95% CI = 0.86, 0.99) were independently associated with malted drink consumption among 6 to 9 year-old children, but not among 10 to 12 year-old children. No association was observed between malted drink consumption and weight status.

CONCLUSIONS

Malted drink consumption is prevalent among Malaysian primary school children, particularly higher among boys, indigenous children and those who lived in the East Coast region of Malaysia. Consuming malted drinks is associated with higher micronutrient intakes and higher levels of physical activity, but not with body weight status.

Effect of orally administered soy milk fermented with Lactobacillus plantarum LAB12 and physical exercise on murine immune responses

Probiotics are live microorganisms that confer health benefits through the gastrointestinal microbiota. This nutritional supplement may benefit athletes who undergo rigorous training by maintaining their gastrointestinal functions and overall health. In this study the influence of moderate physical exercise using a graded treadmill exercise, alone or in combination with the consumption of a soy product fermented with Lactobacillus plantarum LAB12 (LAB12), on tumour necrosis factor alpha (TNF-α) responses was investigated in a murine model. Male BALB/c mice were randomly divided into four groups of six mice each (control, exercise alone, LAB12 and LAB12 + exercise). Mice treated with the potential probiotic LAB12 were orally gavaged for 42 days. At autopsy, blood and spleen from the animals were collected. The splenocytes were cultured in the presence of a mitogen, concanavalin A (Con A). The amount of TNF-α produced by the Con A-stimulated splenocytes was quantified using ELISA, while their proliferation was determined using the [(3)H]-thymidine incorporation method. This study shows that LAB12-supplemented and exercise-induced mice showed marked increase (P<0.05) in cell proliferation compared to the control animals. TNF-α production was suppressed (P<0.05) in the LAB12 group compared to the untreated mice. These results demonstrate that supplementation with LAB12 has immunomodulatory effects, under conditions of moderate physical exercise, which may have implications for human athletes. Further investigation in human trials is warranted to confirm and extrapolate these findings.