Endocrine Abstracts

Introduction: Growth hormone deficiency (GHD) is associated with worsening body composition and growth hormone replacement therapy (GHRT) has shown to improve it in several studies. The objectives of this study were to evaluate the effects of long-term GHRT on body composition in adult patients with GHD andassess, in this population, the agreement between two different methods to measure fat mass that are total body fat mass (FM) and relative fat mass (RFM).

Material and Methods: We conducted a retrospective, longitudinal study in a cohort of patients with GHD under GHRT, followed in the Endocrinology and Nutrition Department of La Paz University Hospital. A total of 79 adult patients (46 women, 33 men), with mean age of 39.1 year-old at starting GHRT, were evaluated for a mean time of 5 years (range 1 to 15 years). RFM, FM, body mass index (BMI) and waist-to-hip (W/H) ratio were measured at baseline and during follow-up, FM was measured by bioelectrical impedance analysis (BIA), RFM was calculated using a linear equation based on height-to-waist ratio proposed by Woolcott et al., [Equation for women: 76–(20 × (height/waist)); equation for men: 64–(20 × (height/waist))]. The evolution of these parameters was assesed using ajusted generalized estimating equation models. The agreement between RFM and FM was estimated using the intraclass correlation coefficient (ICC).

Results: FM measured by BIA did not changesignificantly during the follow-up (P = 0.087). RMF did not change the firsts years, but from the 3rd year of follow-up, it gradually increasedcompared to baseline (3rd year: OR = 2.86; 95% CI = 1.05–7.80; P = 0.04. 4th year: OR = 3.62; 95% CI = 1.25–10.5; P = 0.02. 5th year: OR = 3.41 95%; 95% CI = 1.32–8.8; P = 0.01. 10th year: OR = 5.56; 95% CI = 2.19–14.5; P = 0.003). After the 2nd year of therapy, BMI progressively increased (2nd year: OR = 2.10; 95% CI = 1.22–3.63; P = 0.008. 3rd year: OR = 2.19; CI 95 % = 1.18–4.07; P = 0.01. 4th year: OR = 2.30; 95% CI = 1.02–5.17; P = 0.04. 5th year: OR = 2.84; 95% CI = 1.31–6.17; P = 0.008. 10th year: OR = 7.46; 95% CI = 2.52–22.2; P = 0.0003). W/H ratio did not change significantly (P = 0.06). RFM showed good degree of agreement with FM measured by BIA (ICC 0.78, 95% CI = 0.75–0.81).

Conclusions: 1) In our population, we did not observe improvement in the anthropometric measures during GHRT. 2) RFM showed good agreement with FM measured by BIA, so it could be used to replace this technique when it is not avaliable.