The Association Between Muscle Weakness and Incident Diabetes in Older Mexican Americans.
OBJECTIVE
A natural decline of muscle strength occurs during the aging process; however, preserving muscle strength may lower the rate of many preventable diseases such as diabetes, especially in higher risk populations. The purpose of this study was to examine the sex-specific association between muscle weakness and incident diabetes in older Mexican Americans.


METHODS
Observational, longitudinal study.


METHODS
Urban and rural households in the Southwestern United States.


METHODS
A subsample of 1903 Mexican Americans aged at least 65 years without diabetes at baseline were followed for 19 years.


METHODS
Muscle weakness was assessed with a hand-held dynamometer and was normalized to body weight (normalized grip strength). Male and female participants were categorized as weak if their normalized grip strength was ≤0.46 and ≤0.30, respectively. Sex-stratified Cox proportional hazard regression models were used to determine the association between muscle weakness and incident diabetes (self-reported) when using age as an entry variable and after adjusting for education, employment status, instrumental activities of daily living disability, interview language, marital status, and obesity. A sensitivity analysis was performed to account for influential outliers for the outcome variable (incident diabetes) and the model was re-run.


RESULTS
The hazard ratio for incident diabetes was 1.05 (95% confidence interval: 1.02-1.09; P < .001) in weak vs not-weak male participants and 1.38 (95% confidence interval: 1.35-1.41; P < .001) in weak vs not-weak female participants, after adjusting for relevant covariates.


CONCLUSIONS
Muscle weakness was associated with an increased rate of diabetes in older male and female Mexican Americans. Health professionals should encourage activities that preserve muscle strength, thereby preventing the incidence of diabetes in older Mexican Americans.
Department of Physical Medicine and Rehabilitation, University of Michigan Medicine, Ann Arbor, MI. Electronic address: mcgratry@med.umich.edu.
Ryan
R
McGrath
VA Center for Clinical Management Research, VA Ann Arbor Healthcare System, Ann Arbor, MI.
Brenda M
BM
Vincent
Division of Rehabilitation Sciences, School of Health Professions, University of Texas Medical Branch, Galveston, TX.
Soham
S
Al Snih
Department of Preventative Medicine and Community Health, University of Texas Medical Branch, Galveston, TX.
Kyriakos S
KS
Markides
Department of Physical Medicine and Rehabilitation, University of Michigan Medicine, Ann Arbor, MI.
Mark D
MD
Peterson
D000368:Aged; D000375:Aging; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D017058:Mexican Americans; D018908:Muscle Weakness / Q000150:complications* / Q000175:diagnosis*; D009765:Obesity; D011315:Preventive Medicine; D016016:Proportional Hazards Models; D012424:Rural Population; D057566:Self Report; D015206:Southwestern United States / Q000453:epidemiology; D014505:Urban Population
Aging; handgrip strength; obesity; preventative medicine