Relationships Between Thyroid Hormones, Insulin-Like Growth Factor-1 and Antioxidant Levels in Hypothalamic Amenorrhea and Impact on Bone Metabolism

Horm Metab Res DOI: 10.1055/a-0859-4285Reduced bone mineral density (BMD) in Functional Hypothalamic Amenorrhea (FHA) is mainly related to hypoestrogenism, but other hormonal derangement (reduced conversion of T4–T3 and GH resistance) can play a role. These hormones are involved in antioxidant systems regulation. We evaluated the impact of hormonal alterations, with special focus on low T3 and IGF-1 levels, on antioxidant systems as a link with osteoporosis in FHA. Forty-three FHA patients, 15–34 years, with BMI range 17.3–23.4 kg/m2, were divided in 2 groups according to fT3 levels; group A (n=22), low fT3 (<2.4 pg/ml) and group B (n=21), normal fT3 (≥ 2.4 pg/ml). We evaluated hormonal parameters (fT3, fT4, TSH, IGF-1, FSH, LH, estradiol, DHEAS, testosterone, cortisol), bone metabolism (calcium, phosphorus, 25-OH Vitamin D, PTH, β-crosslaps, bone alkaline phosphatase) and total antioxidant capacity (TAC), expressed as LAG (latency time in radical species appearance using spectrophotometric method). BMD was assessed by DEXA. Group A patients exhibited significantly lower levels of IGF-1 (159.76±14.79 vs. 220.05±15.25 ng/ml) and osteocalcin (17.51±1.14 vs. 21.49±1.56 ng/ml); LAG values were significantly higher in A (66.33±1.74 s) vs. B (54.62±1.74 s). A significant direct correlation was found between both IGF-1 and fT3 with osteocalcin (r²=0.22, p=0.0049 and r²=0.34, p=0.0001, respectively). No difference in LAG between groups according to...
Source: Hormone and Metabolic Research - Category: Endocrinology Authors: Tags: Endocrine Care Source Type: research