Objectives The aim of the study was to assess the influence of obesity on the effect of treatment in patients with non-specific subacute low back pain.
Methods Prospective study included 100 out-patients (40 male and 60 female), aged 48,1 ±10,9 years with subacute non- specific low back pain. Patients were treated at the Institute of Rheumatology, Belgrade, year 2010/12. The body fat was demonstrated as body mass index (BMI), as recommended by the World Health Organisation. According to BMI, patients were divided into three groups: patients with normal weight, overweight and obese patients. All patients underwent the same medication (paracetamol 1500mg/day) and physical therapy (transcutaneus electrical nerve stimulation and exercise) during the two weeks. The intensity of low back pain was measured with Visual Analogue Scale (VAS mm), spinal mobility with finger- floor test (F-F cm) and the functional status with Quebec Back Pain Disability Score (QBPDS). All measurements were done before and after the treatment. Analyses were carried out using SPSS 16.0 (descriptive methods: mean, standard deviation and analytic methods: Kruskal Wollis, Wilcoxon and Mann Whitney test).
Results There were 36 patients with normal weight in Group A (BMI 22,7±1,8), 43 overweight patients in Group B (BMI 27,5±1,3) and 21 obese patients in Group C (BMI 34,5±3,5). Mean pain intensity was 71,7±11,9 before and 25,6 ± 22,5 after the treatment in Group A, 75,3±11,8 before and 29,5±19,9 after the treatment in Group B, and 71,9±11,8 before and 41,9±23,4 after the treatment in Group C. Mean F-F test was 44,2±16,0 before and 19,4 ± 14,9 after the treatment in Group A, 42,9±14,9 before and 22,3±13,8 after the treatment in Group B and 46,7±17,7 before and 28,7±16,4 after the treatment in Group C. Mean QBPDS was 64,0±15,0 before and 27,3±21,8 after the treatment in Group A, 62,3±15,5 before and 29,6±15,9 after the treatment in Group B and 60,0±8,9 before and 38,7±12,9 after the treatment in Group C. Statistically significant differences were registered in pain intensity (VAS), spinal mobility (FF test) and the functional status (QBPDS) for every of the investigated patient groups before and after the treatment (p<0.001). After the treatment, comparison between A and B group did not show differences concerning pain intensity (p=0.262), spinal mobility (p=0.289) and functional status (p=0.247), but differences were found between A and C groups in relation to pain intensity (p=0.012), spinal mobility (p=0.036) and functional status (p=0.019).
Conclusions Our study of patients with non-specific subacute low back pain confirmed different response to treatment between patients with normal weight and obese patients. Therapy effect is lower in patients with obesity than in patients with normal weight.
Jitendra Mangwani, Claire Giles, Mark Mullins, Tuncar Salih, Colin Natali. Obesity and recovery from low back pain: a prospective study to investigate the effect of body mass index on recovery from low back pain. Ann R Coll Surg Engl 2010; 92: 23–26.
Shaw WS, Tveito TH, Woiszwillo MJ, Pransky G. The effect of body mass index on recovery and return to work after onset of work-related low back pain. J Occup Environ Med.2012 Feb;54(2):192-7.
Disclosure of Interest None Declared