Waist circumference and waist-to-hip ratio in carpal tunnel syndrome: a case-control study.
BACKGROUND
The association between carpal tunnel syndrome (CTS) and high body mass index (BMI) and some hand measures is well known. No study has been specifically focused on waist circumference (WC) and waist-to-hip-ratio (WHR). The aim of this prospective case-control study is to evaluate the association between CTS and WC, WHR and other body and hand anthropometric measures.


METHODS
We consecutively enrolled one "idiopathic" CTS case for two controls in 3 outpatient electromyography labs. The main anthropometric measures were BMI, WC, WHR, wrist ratio (WR) and hand ratio (HR). We performed univariate and multivariate analyses.


RESULTS
Female cases and controls were 250 and 474 and male cases and controls were 120 and 273, respectively. At univariate analysis there were differences in many anthropometric measures between cases and controls. At multivariate logistic regression analyses high BMI, WC and WHR and abnormal HR and WR were independent risk factors for CTS. Crossing two categories between BMI, WC and WHR, the overweight subjects, especially females, were at risk only if they had very high WC or high WHR. The risk increased if they were obese.


CONCLUSIONS
High WC/WHR doubles the risk of CTS, the risk further increased if overweight/obese subjects have also very high WC or high WHR. The obese subjects were always at risk regardless of WC and WHR values. Metabolic causes of this association with CTS were hypothesised. BMI is not the only and most powerful body predictor of "idiopathic" CTS, but also WHR and WC should be considered. These measures may not be interchangeable and it may be desirable to consider the utility of their joint use.
EMG Service, Local Health Unit 7, Siena, Italy. Electronic address: m.mondelli@usl7.toscana.it.
Mauro
M
Mondelli
EMG Service, Local Health Unit 7, Siena, Italy.
Alessandro
A
Aretini
Dpt. Neurological, Neurosurgical and Behavioural Sciences, University of Siena, Italy.
Federica
F
Ginanneschi
EMG Service, Local Health Unit 7, "Nottola" Hospital, Montepulciano, Siena, Italy.
Giuseppe
G
Greco
Dpt. Medical and Surgical Sciences, University of Bologna, Italy.
Stefano
S
Mattioli
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000886:Anthropometry; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D016022:Case-Control Studies; D004568:Electrodiagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D016017:Odds Ratio; D015203:Reproducibility of Results; D055105:Waist Circumference / Q000502:physiology*; D049629:Waist-Hip Ratio / Q000379:methods*
Body mass index; Carpal tunnel syndrome; Hand ratio; Nerve entrapment syndrome; Obesity; Waist circumference; Waist-to-hip ratio; Wrist ratio