In a recent study published in the British Journal of Sports Medicine, researchers investigated the association between a complete 10-second one-legged stance and all-cause mortality.
Aging is correlated to the progressive decline in physical health and reduction in elements of aerobic and non-aerobic fitness. Moreover, several studies have shown a reduction in balance after the age of 55 years, thus increasing the odds of sustaining a fatal fall and other adverse outcomes.
About the study
In the present study, researchers assessed the correlation between a complete 10-second one-legged stance (10–second OLS) and all-cause mortality and prognostic data.
The team conducted a prospective cohort study with data collected from the CLINIMEX Exercise open cohort protocol. The study included a total of 1702 participants aged between 51 and 75 years at the time of the first evaluation, performed between 10 February 2019 and 10 December 2020. These participants had voluntarily visited the clinic to assess their aerobic and non-aerobic physical fitness.
The team collected data from all participants, including the gender, age, date of the evaluation, censored date, follow-up time, and date of death (if it has occurred). Anthropometric measurements were also collected with the participants barefoot and wearing minimal clothing. The measurements included the weight, height, girth of the waist, waist-height ratio, body-mass index (BMI), and the sum of six skinfolds, including medial calf, thigh, abdominal, suprailiac, subscapular, and tricipital. Furthermore, clinical data were collected from medical history, taking into account the presence or absence of certain diseases and/or regular medication usage.
During the evaluation, the participants stood on a flat platform, and the static balance was measured as the ability of the patient to complete a 10-second OLS on either foot. This was performed under close supervision of either a physician and/or a nurse to prevent any possible falls or injuries. The barefoot participants were asked to place the dorsal region of the non-support leg on the back of the support leg. Once the correct posture was assumed, a 10-second count was begun, and a total of three attempts were permitted. The participants were subsequently classified as either the ability (YES) or the inability (NO) to complete the test successfully.
The study results showed that 20.4% of the total participants failed the 10-second OLS test and were hence classified as NO. The team noted that the inability to complete the OLS test on either foot increased with age and was found to double for every five-year age interval from the age group of 51 to 55 years. The proportion of NO participants was 4.7% among participants aged between 51 and 55 years, 8.1% between 56 to 60 years, 17.8% between 61 and 65 years, and 36.8% between 66 and 70 years. Notably, 53.6% of participants in the cohort of 71 to 75 years could not complete the 10-second OLS.
During a median follow-up time of seven years, 7.2% of the total participants died, among which 32% of the participants had cancer, 30% due to cardiovascular diseases, 9% due to respiratory system diseases, and 7% due to coronavirus disease 2019 (COVID-19) complications. The team observed that 17.5% and 4.6% of the total deaths occurred in the NO and the YES groups, respectively.
There was no significant difference in sex distribution between the YES and NO groups; however, variables including age, waist-height ratio, and BMI differed substantially between the two cohorts. The NO participants displayed a comparatively unhealthier profile, having a higher proportion of participants diagnosed with hypertension, coronary artery disease, obesity, and dyslipidemia. Interestingly, 37.9% of the NO participants had diabetes mellitus as opposed to 12.6% of the YES participants.
While height was not associated with the ability to complete the 10-second OLS, the highest correlation coefficients were found between the inability to complete the test and age and waist-height ratio. Moreover, Kaplan-Meier survival curves differed remarkably between the YES and the NO cohorts. Cox proportional hazard analysis suggested that the inability to complete the 10-second OLS test successfully was correlated to a substantially higher risk of all-cause mortality.
Overall, the study results showed that the inability to successfully complete a 10-second OLS test among middle-aged and elderly participants was associated with an increased risk of all-cause mortality.