Association of Balance Function With All-Cause and Cause-Specific Mortality Among US Adults

Abstract

Importance: Difficulty maintaining balance is common among individuals aged 40 years or older and increases the risk of falls. However, little is known about the association of balance function with long-term mortality outcomes in adults.

Objective: To investigate the association of balance function with all-cause and cause-specific mortality among US adults.

Design, setting, and participants: A prospective, population-based cohort study of a nationally representative sample of 5816 adults (weighted population, 92 260 641) from the US National Health and Nutrition Examination Survey was conducted from 1999 to 2004. Individuals aged 40 years or older who completed the modified Romberg Test of Standing Balance on Firm and Compliant Support Surfaces were included. Participants were linked to mortality data from the test date through December 31, 2015. Data analysis was conducted from February 1 to June 1, 2020.

Exposures: The modified Romberg Test of Standing Balance on Firm and Compliant Support Surfaces was used to measure balance function and define balance disorder according to sensory input.

Main outcomes and measures: Mortality associated with all causes, cardiovascular disease (CVD), and cancer.

Results: A total of 5816 adults (weighted mean [SE] age, 53.6 [0.2] years; 2897 [49.8%] women) were included in this cohort study. During up to 16.8 years of follow-up (median, 12.5 years; 68 919 person-years), 1530 deaths occurred, including 342 associated with CVD and 364 associated with cancer. Participants with balance disorder were at a higher risk of death from all causes, CVD, and cancer. After adjusting for sociodemographic characteristics, lifestyle factors, and chronic conditions, the hazard ratios (HRs) among participants with balance disorder compared with those without balance disorder were 1.44 (95% CI, 1.23-1.69) for all-cause mortality, 1.65 (95% CI, 1.17-2.31) for CVD mortality, and 1.37 (95% CI, 1.03-1.83) for cancer mortality. Furthermore, vestibular balance disorder was associated with increased mortality from all causes (HR, 1.31; 95% CI, 1.08-1.58), CVD (HR, 1.59; 95% CI, 1.12-2.27), and cancer (HR, 1.39; 95% CI, 1.04-1.86).

Conclusions and relevance: In this nationally representative sample of US adults, balance disorder was associated with an increased risk of all-cause, CVD, and cancer mortality. Further studies are needed to confirm these findings and evaluate whether the observed associations represent a causal biological phenomenon and, if so, whether the effect is modifiable with a multicomponent exercise program.

Figure 1.. Flowchart of Balance Disorder Assessment

After excluding deaths that occurred within the first 24 months of follow-up (n = 88; 58 participants with balance disorder), 5816 adults (2509 with balance disorder) were included in the final analysis.

Figure 2.. Adjusted Hazard Ratios of All-Cause and Cause-Specific Mortality Comparing Balance Disorder With No Balance Disorder, National Health and Nutrition Examination Survey, 1999-2015

Hazard ratios were adjusted for age (5-year intervals), sex (male or female), race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, and other), educational attainment (less than high school, high school graduate, above high school), family poverty status (ratio of family income to the federal poverty level: <1.30, 1.30-3.49, or ≥3.5), leisure-time physical activity (inactive or active), alcohol consumption (0, 0.1-4.9, 5-14.9, 15-29.9, or ≥30 g/d), body mass index (calculated as weight in kilograms divided by height in meters squared) (<18.5, 18.5-24.9, 25-29.9, and ≥30), smoking status (never, former <20 pack-years, former ≥20 pack-years, former unknown pack-years, current <20 pack-years, and current ≥20 pack-years), hypertension (yes or no), hypercholesterolemia (yes or no), history of diabetes (yes or no), history of cardiovascular disease (CVD) (yes or no), history of cancer (yes or no), family history of diabetes (yes or no), and family history of CVD (yes or no).

Figure 3.. Stratified Hazard Ratios and 95% CIs for All-Cause and Cause-Specific Mortality According to Balance Disorder

All-cause, cardiovascular disease–specific, and cancer-specific mortality. BMI indicates body mass index (calculated as weight in kilograms divided by height in meters squared). Balance disorder was defined as no (successful Romberg test) vs yes (unsuccessful Romberg test). The models were adjusted for age (5-year intervals), sex (male or female), race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, and other), education attainment (less than high school, high school graduate, above high school), family poverty status (ratio of family income to the federal poverty level: <1.30, 1.30-3.49, or ≥3.5), leisure-time physical activity (inactive or active), alcohol consumption (0, 0.1-4.9, 5-14.9, 15-29.9, or ≥30 g/d), body mass index BMI (<18.5, 18.5-24.9, 25.0-29.9, and ≥30.0), smoking status (never, former <20 pack-years, former ≥20 pack-years, former unknown pack-years, current <20 pack-years, and current ≥20 pack-years), hypertension (yes or no), hypercholesterolemia (yes or no), history of diabetes (yes or no), history of cardiovascular disease (CVD) (yes or no), history of cancer (yes or no), family history of diabetes (yes or no), and family history of CVD (yes or no), except the corresponding subgroup variate. ^aLeisure-time physical activity level was defined by engaging in no (inactive) or any (active) moderate or vigorous recreational physical activity over the past 30 days. ^bChronic diseases included CVD (not included in CVD mortality), cancer (not included in cancer mortality), and diabetes.