Learning Objective #1: Describe the influneces of diabetes on activities of daily living (ADL) and instrumental activities of daily living (IADL) in Mexican and Euro-American elders

Learning Objective #2: Contrast causal effects of diabetes, range of motion, muscle strength, and physical limitations as determinants of ADL and IADL in different cultural contexts

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Activities of Daily Living (ADLs) and Instrumental Activities of Daily Living (IADL) decline with aging. The Disablement Process Model (DPM) is the theoretical basis for this study of diabetes, ADLs and IADLs. The research evaluates effects of diabetes on ADLs and IADLs, and compares effects across Mexican-Americans (MA) and European-Americans (EA). Structural equation modeling compares direct paths from diabetes to ADLs and IADLs, and mediated effects through range of motion (ROM), muscle strength, and physical limitations.

METHODS. Subjects were elder (>65 years; n = 394 MA, and n = 355 EA)participants in the San Antonio Longitudinal Study of Aging. ADLs/IADLs were measured by the Katz Scale and Older Americans Resources Survey respectively. ROM was assessed with goniometer for upper/lower body joints. Upper/lower body muscle strength was measured with handheld and JAMAR dynamometers. Physical limitations were upper/lower body scores from the Nagi Index.

RESULTS: The model did not equally fit data from both groups (CFI = .76, RMSEA = .07). MAs showed significant direct influence of diabetes on ADLs but not IADLs. EA effects were opposite, showing effects on IADLs but not ADLs. For MAs, diabetes showed important indirect effects on both ADLs and IADLs through ROM, strength, and physical limitations. Diabetic status in EAs had no indirect effect on ADLs, and a minor one to IADLs. A conspicuous difference was the large direct effect of physical limitations on both ADLs/IADLs for MAs, with EAs showing far smaller effects. ADLs/IADLs were well explained in the MA group (R2 = .68 and .63), but only modestly in the EA group (R2 = .34 and .25).

IMPLICATIONS: For MAs the DPM was supported for physical limitations, ADL, and IADL. The EA model showed minor effects on IADL and was far less informative. Contrasts in models underscore the importance of cultural differences.