Associations of cardiorespiratory fitness, physical activity, and obesity with metabolic syndrome in Hong Kong Chinese midlife women.

BACKGROUND: Several studies have simultaneously examined physical activity (PA) and cardiorespiratory fitness (CRF) with metabolic syndrome (MS). However, the independent roles of both PA and CRF with MS are less firmly established. The combined contributions of PA and CRF with MS are less studied, particularly among Chinese women. There is uncertainty over the extent to which metabolically healthy but overweight/obese individuals have a higher CRF level. METHODS: The sample included 184 Chinese women aged 55 to 69 years with available metabolic data and lifestyle factors. PA was assessed by self-reported questionnaire; CRF was assessed by maximal oxygen consumption (VO2max) during a symptom-limited maximal exercise test on a cycle ergometer. Metabolically healthy/abnormal was defined on the basis of absence or presence of MS. Overweight was defined as a body mass index (BMI) of ≥ 23 kg/m2 and obese was defined as a BMI of ≥ 25 kg/m2. RESULTS: The prevalence of MS was 21.7%. PA was inversely associated with the prevalence of MS after adjustment for age, BMI, and dietary total calories intake, but the association was eliminated after further adjustment for CRF. CRF was inversely associated with the prevalence of MS independent of age, BMI, and dietary total calories intake, and the association remained significant after further adjustment for PA. In the PA and CRF combined analysis, compared with those in the lowest tertile of PA (inactive) and lowest tertile of CRF (unfit), the OR (95%CI) of having MS was 0.31 (0.09-1.06) for subjects in the higher tertiles (2nd-3rd) of PA (active) but were unfit, 0.23 (0.06-0.88) for subjects who were inactive but in the higher tertiles (2nd-3rd) of CRF (fit), and 0.14 (0.04-0.45) for subjects who were active and fit. Metabolically healthy but overweight/obese subjects had a higher CRF level than their metabolically abnormal and overweight/obese peers. However, the difference did not reach statistically significance. CONCLUSIONS: CRF has greater association with the prevalence of MS compared with PA in Chinese midlife women. The interrelationships between CRF, obesity, and MS needs further study.

Impact of the COVID-19 pandemic on sports and exercise.

BACKGROUND: COVID-19 is a droplet-transmitted potentially fatal coronavirus pandemic affecting the world in 2020. The WHO recommended social distancing and human-to-human contact was discouraged to control the transmission. It has put many countries in a state of lockdown and sporting events (including the 2020 Olympics) have been affected. Participation in sports and exercise, typically regarded as healthy activities, were also debated. The local professional football leagues, governed by the Hong Kong Football Association, ultimately postponed all matches after much deliberation on the transmission risk for the spectators and on-field players. Large spectating crowds are well-known to be infectious hazards, but the infection risk for on-field players is less recognized. Aside from watching professionals exercise, many people opted to hike in the countryside during the weekends to avoid city crowds. This led to a widespread discussion on the issue of wearing a facemask during outdoor activities. METHODS: A small sample of video footage of professional football players were analysed to track each players' time of close body contact and frequency of infection-risky behaviours to investigate the risk of virus transmission during football games.To investigate the physiological effect of wearing a facemask during exercise, we conducted a controlled laboratory, within-subject, repeated measures study of 23 healthy volunteers of various sporting backgrounds. They underwent graded treadmill walking at 4 km per hour for 6 min with and without wearing a surgical mask in a randomized order with sufficient resting time in between trials. The heart rate and the rate of perceived exertion (RPE) were recorded. RESULTS: In a 90 min match, the average duration of close contact between professional football players was 19 min and each player performed an average of 52 episodes of infection-risky behaviours. The heart rate and RPE of subjects wearing a facemask was 128 beats per minute and 12.7 respectively. In those without a facemask, the results were a heart rate of 124 beats per minute and a RPE of 10.8. CONCLUSION: This suggests that the infection risk was high for the players, even without spectators. The laboratory study to investigate the physiological effect of wearing a facemask found that it significantly elevated heart rate and perceived exertion. Those participating in exercise need to be aware that facemasks increase the physiological burden of the body, especially in those with multiple underlying comorbidities. Elite athletes, especially those training for the upcoming Olympics, need to balance and reschedule their training regime to balance the risk of deconditioning versus the risk of infection. The multiple infection-control measures imposed by the Hong Kong national team training centre was highlighted to help strike this balance. Amidst a global pandemic affecting millions; staying active is good, but staying safe is paramount.

Peak oxygen uptake, six-minute walk distance, six-meter walk speed, and pulse pressure as predictors of seven year all-cause and cardiovascular mortality in community-living older adults.

Cardiorespiratory fitness and physical performance measures predict mortality. It is uncertain whether pulse pressure (PP), a measure that is routinely available in healthcare settings, may also predict mortality with a comparable degree of accuracy. In a study consisting of older adults (709 men and 467 women) living in the community, we examined the relationship between PP, peak oxygen uptake (VO2 peak), 6-minute walk distance (6MWD) and 6-meter walking speed (6MWS) and seven year all-cause and cardiovascular mortality. Receiver operator characteristic (ROC) curve was used to compare predictive performance. In the prediction of all-cause mortality, in men, 6MWD, 6MWS and PP all have comparable area under curve (AUC) values compared with VO2 peak: 0.736, 0.723, 0.736 and 0.734 respectively. Similar results were observed for women, although all the AUC values were slightly lower (corresponding values were 0.723, 0.713, 0.702 and 0.747 respectively). For cardiovascular mortality, the findings are similar although in men all AUC values were higher. We conclude that PP predicts 7 year all-cause and cardiovascular mortality in older adults with an accuracy similar to VO2 peak, 6MWD and 6MWS, although the association is less strong in women.

The Role of Dietary Patterns in the Contribution of Cardiorespiratory Fitness in Community-Dwelling Older Chinese Adults in Hong Kong.

OBJECTIVE: We examined the influence of various dietary patterns on cardiorespiratory fitness (CRF) expressed as peak oxygen uptake (VO2peak), taking into account demographics and lifestyle risk factors. DESIGN: Prospective cohort study. PARTICIPANTS AND METHODS: We conducted multivariate linear regression analyses using available data from a cohort of community-dwelling older Chinese adults (752 men, 483 women) in Hong Kong. Baseline interviewer-administered questionnaires covered dietary intake estimation and dietary pattern generation from the food frequency questionnaire, demographic and lifestyle factors, self-reported medical history, as well as frailty status. VO2peak at the 7-year follow-up was measured using symptom-limited maximal exercise testing on an electrically braked bicycle ergometer. RESULTS: In men, baseline Diet Quality Index-International (DQI-I) score (ß = 0.044, P = .013) and Okinawan diet score (ß = 0.265, P = .014) was independently associated with age-adjusted VO2peak at the 7-year follow-up. The significant association was only retained for the Okinawan diet score in the multivariate adjusted model (ß = 0.227, P = .039). Dietary pattern scores including the Dietary Approaches to Stop Hypertension (DASH) score, Mediterranean-DASH Intervention for Neurodegenerative Delay Diet score, Mediterranean Diet Score, and 3 other pattern scores derived by factor analysis were not associated with VO2peak. In women, none of the dietary pattern scores at baseline was associated with VO2peak in both the age-adjusted and multivariate-adjusted models. CONCLUSIONS/IMPLICATIONS: A higher Okinawan diet score was associated with a higher 7-year CRF in community-dwelling Chinese older men. Further studies are warranted to examine the underlying mechanisms on how the Okinawan diet influences CRF.

Authentication of Panax ginseng and Panax quinquefolius using amplified fragment length polymorphism (AFLP) and directed amplification of minisatellite region DNA (DAMD).

AFLP profiles characteristic to Panax ginseng and Panax quinquefolius were generated using primers E-AGG/M-CAA. P. ginseng samples from different farms in China and Korea are homogeneous genetically [similarity index (SI) = 0.88-0.99], whereas samples of P. quinquefolius from different sources are much more heterogeneous (SI = 0.64-0.96). Detailed analysis of one of the polymorphic bands in P. ginseng led to the identification of a minisatellite Pg2, which contains eight repeats of 5'-AGGACTCATCACATTGTTACTC. The minisatellite DNA was consequently used in directed amplification minisatellite region DNA analysis to authenticate the two ginsengs.

Fitness, fatness and survival in elderly populations.

This study examines the relative importance of fitness versus fatness in predicting mortality in elderly populations aged 70 years and over, and whether fitness may account for the 'paradoxical' relationship between better survival and increasing weight. Four thousand community-living Chinese men and women aged 65 years or over were recruited and stratified so that approximately 33% were in each of the age groups: 65-69, 70-74, and 75 or above. Medical history, height, weight, waist-hip ratio, body composition using DEXA, and walking speed were obtained. They were followed up for a mean of 7.0 years to ascertain death. Compared with the high fitness category, those in the moderate and low categories have a 43% and 68% increased risk of mortality at 7 years adjusting for multiple confounders. When mortality risk according to various fatness indicators was examined, only the lowest quartile of BMI, BFI, and FLMR conferred statistically significant increased risk. Fitness categories were significantly associated with all fatness indicators. The finding of fewer people in the high fitness category among the highest quartiles of other fatness indicators suggests that fitness is not the underlying mechanism for the obesity paradox. Within each quartile of fatness indicator, there was a significant trend towards reduced mortality with increasing fitness. In conclusion, the study confirms the beneficial effects of cardiorespiratory fitness on mortality but does not explain the 'obesity paradox'. The findings underscore the importance of maintaining physical fitness through exercise and re-confirm the importance of weight maintenance in reducing mortality risk.

Cardiorespiratory fitness and its association with body composition and physical activity in Hong Kong Chinese women aged from 55 to 94 years.

BACKGROUND: Low levels of cardiorespiratory fitness have proven to be associated with a higher risk of premature death from all causes, specifically from cardiovascular disease. However, there has been no study conducted to describe the cardiorespiratory fitness normative values in Chinese midlife and elderly. OBJECTIVES: To provide normative values of cardiorespiratory fitness expressed as maximal oxygen uptake (VO(2max)) and its association with body composition and physical activity in Chinese midlife and elderly women in Hong Kong. METHODS: 659 Chinese women aged from 55 to 94 years were recruited from two existing cohorts: the carotid atherosclerosis in women Hong Kong cohort study and the Osteoporotic Fractures in Women (MsOS) Hong Kong cohort study. Symptom-limited maximal exercise testing on an electrically braked bicycle ergometer was performed to assess VO(2max), where the subject was connected to a calibrated metabolic cart for gas analysis. Their body composition and physical activity data were also assessed. RESULTS: The body mass index was 23.4 kg/m(2) and the mean fat mass and lean body mass were 16.6 kg and 37.3 kg, respectively. The mean VO(2max) was 20.3±4.1 ml/kg/min (range, 7.9-35.7 ml/kg/min). VO(2max) decreased with age, with the rate of decline 0.25 ml/kg/min/yr (7.1% per decade). In a subgroup of 475 women from the MsOS study, the decline in VO(2max) was found to depend on ageing (ß=0.31, P<0.001), body mass index (ß=-0.30, P<0.001) and levels of physical activity (ß=0.02, P<0.001). Fat mass was also independently associated with VO(2max) (ß=-0.20, P<0.001). CONCLUSIONS: This study describes the normative values of VO(2max) in a sample of Chinese midlife and elderly women which provides a valuable reference to assess health and fitness in Chinese elderly. Results from this study also suggested that body composition and levels of physical activity were important determinants of the age-related decline in VO(2max).

Generation of a sequence characterized amplified region probe for authentication of crocodilian species.

A 209-base pair (bp) crocodilian-specific sequence characterized amplified region (SCAR) was identified from a 425-bp randomly amplified polymorphic DNA (RAPD) fragment. The 209-bp SCAR was produced from amplifications of DNA extracted from fresh and/or dry meat samples from at least three species of Crocodylus, Caiman crocodylus, and Alligator mississippiensis. No amplification was observed from DNA of other common animal species. The use of SCAR opens the way for quick authentication of crocodilian samples for conservation biology and trade regulation.