Role of Body Mass Index in Acute Charcot Neuroarthropathy

SLR - March 2013 - Nicholson

References: Ross A., Mendicino R., Catanzariti A., Role of Body Mass Index in Acute Charcot Neuroarthropathy. Foot and Ankle Surgery, Volume 53, No. 1 January 2013

Scientific Literature Review

Reviewed By: Ciara Nicholson, DPM
Residency Program: St. Vincent Hospital, Worcester, MA

Podiatric Relevance:
As the prevalence of obesity in the United States continues to rise, the contribution of an increased body mass index to the onset of chronic diseases, such as diabetes and cardiovascular disease, has become a particular area of interest in medicine. In regards to lower extremity pathologies, increased body weight has been postulated to be a contributing factor to repetitive injuries resulting from strain. With these relationships in mind, the authors of this study postulated that incidence of obesity would further be reflected in diabetic populations with acute Charcot neuroarthropathy (CN).

Methods:
A retrospective study was conducted on a total of 49 neuropathic patients (19 M, 30 F) from the Foot and Ankle Institute of the Western Pennsylvania Hospital from July 2006 to November 2011. Patients were selected based upon the following inclusion criteria: availability of complete medical records relative to the variables of interest, documented diabetic peripheral neuropathy with or without the diagnosis of Charcot foot, and documented BMI or height and weight. In total, 20 Charcot-positive patients and 29 neuropathic diabetic patients without Charcot foot (controls) fit the aforementioned demographics. Among the final data set, 28 were insulin dependent, with 15 of all CN patients and 13 of all non-CN patients exhibiting insulin independence. An adjusted logistic regression model was conducted to determine the influence of BMI and other predictors, specifically: age, PVD, type of diabetes mellitus, and the development of Charcot foot (dependent variable).

Results:
Adjusted logistic regression models were used to evaluate the relationship between BMI and Charcot status. Age, PVD, and type of diabetes mellitus were entered in block 1 and BMI in block 2. When analyzed, the independent variables entered in block 1 were not statistically significant in relation to Charcot status. Of the evaluated independent predictors, only one type of diabetes mellitus was found statistically significant when related to Charcot status. The odds of a patient with insulin-dependent diabetes mellitus having CN was evaluated as being 3.90 times greater than that of a non-insulin dependent diabetes mellitus patient. After controlling for all block 1 variables, the relationship between BMI and Charcot status was evaluated, with BMI failing to account for significant variance in the model.

Conclusions:
The authors of this study suggest no observed relationship between BMI and increased risk of acute Charcot neuroarthropathy, based upon the results noted. In considering the analyzed predictors, only diabetes classifications were found to correlate with CN. Specifically, insulin dependence was noted as being a risk factor for CN.