Perturbed insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 are not associated with chronic widespread pain in men: results from the European Male Ageing Study.
McBeth J., Tajar A., O'Neill TW., Macfarlane GJ., Pye SR., Bartfai G., Boonen S., Bouillon R., Casanueva F., Finn JD., Forti G., Giwercman A., Han TS., Huhtaniemi IT., Kula K., Lean MEJ., Pendleton N., Punab M., Silman AJ., Vanderschueren D., Wu FCW.
OBJECTIVE: To determine whether perturbations of insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 (IGFBP-3) were associated with the presence of chronic widespread pain (CWP) in men. METHODS: The European Male Ageing Study (EMAS) is an 8-center population-based study of men aged 40-79 years recruited from population registers. A questionnaire asked about the presence and duration of musculoskeletal pain, from which subjects reporting CWP were identified. Subjects also had an interviewer-assisted questionnaire: levels of physical activity and mood were assessed, and height and weight were measured. IGF-1 and IGFBP-3 were assayed from a fasting blood sample. Logistic regression models were used to determine the association between IGF measures and CWP. Results were expressed as odds ratios or relative risk ratios. RESULTS: A total of 3206 subjects provided full data. Of those, 1314 (39.0%) reported no pain in the past month and 278 (8.3%) reported pain that satisfied criteria for CWP. IGF-1 concentrations were similar among subjects who reported no pain and those with CWP: 131.5 mg/l and 128.4 mg/l, respectively. This was true also for IGFBP-3 (4.3 and 4.3 mg/l). Obesity was associated with low IGF-1 and a high IGFBP-3/IGF-1 ratio, indicating less bioavailable IGF-1, irrespective of pain status. This relationship persisted after adjustment for comorbidities, depression, smoking, alcohol consumption, and quality of life. CONCLUSION: Overall CWP was not associated with perturbations in IGF-1 and IGFBP-3 concentrations. Hypofunctioning of the axis was noted among subjects who were obese and this was not specific to CWP. These data suggest that IGF-1 is unlikely to be etiologically important in relation to CWP, although the relationship with growth hormone remains to be elucidated.