The inter-relationship between obesity and symptomatology of knee osteoarthritis in older women: a cross-sectional study

Abstract

Objective: To define a cut-off point of osteoarthritis (OA) symptomatology that becomes serious in older women. Methodology: the cross-sectional study with a quantitative and comparative approach, in which the data were collected by structured interview, informing age, body mass, height, and the filling out the Western Ontario and McMaster Universities questionnaire (WOMAC). The found results were sub-grouped by general WOMAC index (< 39 and ≥ 39 points) and by classification of body mass index - BMI [eutrophic (E); overweight (O); and obese (OB)] for post-comparisons. Inferential statistics: the independent t-test, analysis of variance (ANOVA-one way), a Receiver Operator Characteristic Curve (Curve ROC), and the Youden test for robustness were used, considering a p < 0.05. Results: The participants of the study were 79 older women distributed by BMI classification (E = 24; O = 28 and OB = 27 participants) with a mean age of (E = 67.1 ± 6.4; O = 68.4 ± 5.8; OB = 68.5 ± 5.3 years old). When analyzed by WOMAC index subgroups, the ≥ 39 WOMAC subgroup showed a BMI bigger than the < 39 WOMAC subgroup (p < 0.05). At last, when analyzing the robustness of variations described by the Youden test, the cut-off point was 29.78 kg/m2. Conclusion: The development of osteoarthritis is positively associated with the BMI index in older people, and the cut-off point detected by the Youden test can be a relevant indicator of increased risk for the development of osteoarthritis.