In:
The Journal of Clinical Endocrinology & Metabolism, The Endocrine Society, Vol. 91, No. 7 ( 2006-07-01), p. 2732-2737
Abstract:
Context: Recent studies showed that male reproductive health problems, such as cryptorchidism, hypospadias, testicular cancer, and low sperm quality, are more prevalent in Denmark than in Finland. Objectives: We hypothesized that, if fetal testicular dysgenesis contributed to these observations, differences in gonadal development and the hypothalamus-pituitary-testis axis would already be detectable perinatally. Thus, we investigated healthy newborn boys in both countries. Design: This was a prospective, longitudinal population-based study. Setting: Two primary obstetric centers were included at the University Hospitals of Copenhagen, Denmark, and Turku, Finland. Participants: The participants of the study included 633 Danish and 1044 Finnish boys, born at term with appropriate weight for gestational age. Interventions: Ultrasound determination of testis size at 0, 3, and 18 months and blood sampling (n = 727) at 3 months were analyzed. Main Outcome Measures: Testicular volume and reproductive hormones were measured. Results: Testis volume was significantly higher at all ages in Finnish than in Danish boys (medians, 98 vs. 95, 185 vs. 119, and 188 vs. 136 mm3, respectively; P & lt; 0.00001). Testis growth from birth to 3 months was larger in Finnish than in Danish boys (mean, 75 vs. 26 mm3; P & lt; 0.0001). Serum hormone levels were higher in Finnish than Danish boys for inhibin B (median, 456 vs. 385 pg/ml; P & lt; 0.0001), FSH (1.33 vs. 1.21 IU/liter; P & lt; 0.036), and SHBG (143 vs. 136 nmol/liter; P & lt; 0.022). Inhibin B was significantly positively correlated to testicular volume (r = 0.25; P & lt; 0.006). Conclusions: The larger testes and higher inhibin B levels most likely represent a bigger volume of seminiferous tubules in Finnish compared with Danish boys. Although this phenomenon may be attributable to a genetic difference between the two countries, it may also reflect environmental factors influencing testicular development.
Type of Medium:
Online Resource
ISSN:
0021-972X
,
1945-7197
DOI:
10.1210/jc.2005-2443
Language:
English
Publisher:
The Endocrine Society
Publication Date:
2006
detail.hit.zdb_id:
2026217-6
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