The ten-second balance test is an aging biomarker

Your biological age does not necessarily correlate with your chronological age. Your mental and physical capabilities can be greater or less than a typical person of your age which portends for your overall health and longevity. There are numerous physiological variables that correlate with your overall health and biological age including blood glucose levels, cardiovascular fitness (e.g. VO2max), blood cholesterol, BMI (or waist-to-hip ratio) WBC and RBC counts, telomere length, lung function, etc. Not surprisingly many are also associated with longevity and delayed mortality so that your biological age can be a lot younger than your chronological (actual) age (QH).

There are a number of biomarkers that are associated with longevity and healthy aging. One of my favorites is VO2max, which is is the maximum rate of oxygen consumption during strenuous exercise, and is an indicator of cardiovascular fitness. Other longevity biomarkers are less demanding to measure than VO2max. In a previous post, I described a paper that assessed grip strength, and found that "[e]ach 5-kg (11-lb) increment of grip strength below these thresholds was tied to a 20 percent increase for women and a 16 percent increase for men in the risk of death from all causes."

Another study examined the link between physical capability at middle age (age 53) and all-cause mortality over the next 13 years. Physical capability was determined by a combination of three tests: the grip strength test, chair rise time, and standing balance time. The latter was "the longest time, up to a maximum of 30 seconds, participants could maintain a one-legged stance in a standard position with their eyes closed." The researchers found that the bottom 20% performers on the physical tests had a mortality rate 3.68 times that of the top 20% (QH).

A recent article in The New York Times emphasized the importance of balance for healthy aging. Falls rank as the second top cause for unintentional injury deaths globally. Balance declines as one ages with multiple age-related factors contributing to balance issues from vision problems to the slowing of nerve signals to weakening muscles.

To test balance, the article focuses on the 10 second balance test (rather than the standing balance time described above). The subject attempts to stand on one leg for 10 seconds or longer (10-s OLS). A new paper investigated mortality rates of those who could pass the test versus those who could not.

In the study, 1702 individuals aged between 51 and 75 years were given the 10 second balance test along with clinical evaluations and anthropometric measurements (i.e. physical characteristics such as weight, BMI, etc.). Roughly 20% of participants could not pass the 10-s OLS (NO category). Survival rates were measured for both the NO group and the YES group (passed the test) over a median observation period of 7 years.

During that time, 7.2% of the participants passed away, with 4.6% classified as YES on the 10-second OLS and 17.5% as NO. After accounting for age, gender, body mass index, and existing health conditions in a modified model, the hazard ratio for overall mortality for individuals classified as NO was 1.84 (p < 0.001) compared to the YES group.

Importantly, adding the 10-s OLS to a model containing established risk factors was associated with significantly improved mortality risk prediction. Thus, the ability to complete the 10-s OLS provides relevant prognostic information beyond age, sex and several other anthropometric and clinical variables

A final note is that one can readily observe the steep decline in 10-s OLS proficiency as one ages. In the 56-60 age group the YES percentage was ~90%, but then there is a steady decrease to the 81-85 age group in which YES represented only 10% of all subjects (Figure 1). The green line in Figure 1 provides direct visual evidence that the ten-second balance test can serve as an informative aging biomarker.

Figure 1. "YES= ability or NO= inability to complete the 10-s one-legged stance test according to age groups. This figure includes information from individuals of a wider age range than the one included for analysis in this study as mentioned previously" (from Araujo et al. BMJ Sports Medicine, 2022). The study only used people aged 51 to 75.