Modic changes in the lumbar spine and their association with body composition, fat distribution and intervertebral disc height – a 3.0 T-MRI study
BACKGROUND Normal weight obesity (NWO) is defined as percentage body fat (%BF) above 30% or %BF in the upper tertile in normal weight subjects. Using these criteria, we assessed lipid profiles, glucose metabolism parameters, blood pressure and regional fat in 91 premenopausal women with NWO and 54 age-matched healthy controls. METHODS We measured total cholesterol, high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides (TG), glucose, insulin, visfatin and adiponectin.%BF, abdominal fat (Android) and hip fat (Gynoid) were measured by dual-energy X-ray absorptiometry. Insulin resistance was evaluated by homoeostasis model assessment (HOMA-IR). RESULTS Women with NWO had higher diastolic blood pressure (DBP) (P = 0·003), LDL (P = 0·048), TG (P = 0·004) Android (P = 0·008) and Gynoid (P = 0·007) levels, but lower HDL (P = 0·009) than healthy controls. The NWO women had one (P = 0·041), two (P = 0·007) or three (P = 0·002) metabolic syndrome components more frequently than the controls. Across %BF tertiles, the number of metabolic syndrome components significantly increased (R = 0·21; P = 0·02), as did Gynoid (R = 0·83; P < 0·001) and Android (R = 0·81; P < 0·001) levels. Android (but not Gynoid) level was linearly associated with DBP (R = 0·194; P = 0·019), HDL (R = -0·295; P = 0·0004) and TG (R = 0·183; P = 0·031). Visfatin and adiponectin levels were comparable in both groups. Visfatin was inversely correlated with cholesterol, LDL and HOMA-IR. Adiponectin was inversely correlated with the Android/Gynoid and Android/Total fat ratios. CONCLUSIONS Compared with healthy controls, women with NWO had higher DBP, TG, LDL, and regional fat and lower HDL. These findings seem to be associated more with excess Android fat than excess %BF.