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- Hagmar, L, et al.
(author)
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Plasma concentrations of persistent organochlorines in relation to thyrotropin and thyroid hormone levels in women
- 2001
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In: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 0340-0131 .- 1432-1246. ; 74:3, s. 8-184
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Journal article (peer-reviewed)abstract
- OBJECTIVES: There is a concern that persistent organohalogen toxicants, such as polychlorinated biphenyls (PCBs), might display endocrine-disrupting effects in exposed populations. In this study the correlations between PCBs and thyrotropin (TSH) and thyroid hormone concentrations in plasma were assessed in adult women.METHODS: The study group consisted of 182 fishermen's wives from the Swedish east coast, with a median age of 42 years (range 23-62) and a median current consumption of contaminated fatty fish from the Baltic Sea of two meals per month (range 0-12). TSH, free (FT3) and total (TT3) triiodothyronine and free (FT4) and total (TT4) thyroxin in plasma were analyzed by immunofluorometric assays, and 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) in plasma was analyzed by gas chromatography with electron capture detection. Twenty other PCB and two hydroxy-PCB congeners were analyzed in subgroups of the women. Plasma lipid analyses were performed with enzymatic techniques.RESULTS: The CB-153 concentration in plasma (range 16-776 ng/g lipid) was negatively correlated with the TT3 concentrations (range 1.0-3.0 nmol/l, rs = -0.29, P < 0.001). This association remained after age adjustment.CONCLUSIONS: The present study gives some support for the notion that dietary exposure to persistent organochlorine compounds (POCs) might weakly affect peripheral thyroid hormone concentrations in adult women.
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| 2. |
- Erfurth, E M, et al.
(author)
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The negative association between serum free testosterone and leptin is dependent on insulin-like growth factor-binding protein 1 in healthy young and middle-aged men
- 2000
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In: Clinical Endocrinology. - : Wiley. - 0300-0664. ; 52:4, s. 8-493
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Previous studies have shown that serum levels of testosterone correlate negatively with leptin and positively with insulin-like growth factor binding protein 1 (IGFBP-1). The present study examined whether these associations are linked.DESIGN AND PATIENTS: The association between serum levels of IGFBP-1, free testosterone and insulin on one hand and leptin on the other hand were investigated in 38 healthy men with a median age of 48 years (range 23-62 years).RESULTS: Univariate analyses revealed that serum levels of leptin correlated negatively with serum free testosterone (r = - 0.42, P = 0.008) and with serum IGFBP-1 (r = - 0. 45, P = 0.005) and positively with body mass index (BMI; r = 0.46, P = 0.003) and serum insulin (r = 0.45, P = 0.004). Serum free testosterone correlated with IGFBP-1 (r = 0.42, P = 0.008) but not with serum insulin (r = - 0.08, ns). The correlations between leptin and free testosterone and between leptin and IGFBP-1 remained significant after adjustement for the influences of BMI and insulin. Forward stepwise multiple regression when BMI, insulin, testosterone and IGFBP-1 were entered in a model as independent variables and leptin as the dependent variable showed that BMI and IGFBP-1 were independent predictors of circulating leptin. These two parameters yielded an r 2 of 0.38, thereby together explaining approximately 40% of serum leptin.CONCLUSION: Serum levels of free testosterone and IGFBP-1 correlate negatively with serum leptin in healthy nonobese men but this influence is dependent on the influence of IGFBP-1. The study therefore suggests an important impact of IGFBP-1 on the regulation of circulating leptin in young and middle-aged men.
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