| 1. |
- Huhtaniemi, Ilpo T., et al.
(författare)
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Comparison of serum testosterone and estradiol measurements in 3174 European men using platform immunoassay and mass spectrometry; relevance for the diagnostics in aging men
- 2012
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Ingår i: European Journal of Endocrinology. - 1479-683X. ; 166:6, s. 983-991
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Tidskriftsartikel (refereegranskat)abstract
- Background: The limitations of serum testosterone and estradiol (E-2) measurements using nonextraction platform immunoassays (IAs) are widely recognized. Switching to more specific mass spectrometry (MS)-based methods has been advocated, but directly comparative data on the two methods are scarce. Methods: We compared serum testosterone and E-2 measurements in a large sample of middle-aged/elderly men using a common platform IA and a gas chromatography (GC)-MS method, in order to assess their limitations and advantages, and to diagnose male hypogonadism. Of subjects from the European Male Aging Study (n = 3174; age 40-79 years), peripheral serum testosterone and E-2 were analyzed using established commercial platform IAs (Roche Diagnostics E170) and in-house GC MS methods. Results: Over a broad concentration range, serum testosterone concentration measured by IA and MS showed high correlation (R=0.93, P<0.001), which was less robust in the hypogonadal range (<11 nmol/l; R=0.72, P<0.001). The IA/MS correlation was weaker in E-2 measurements (R=0.32, P<0.001, at E-2 <40.8 pmol/l, and R=0.74, P<0.001, at E-2 >40.8 pmol/l). Using MS as the comparator method, IA ascertained low testosterone compatible with hypogonadism (<11 nmol/l), with 75% sensitivity and 96.3% specificity. The same parameters with IA for the detection of low E-2 (<40.7 pmol/l) were 13.3 and 99.3%, and for high E-2 (>120 pmol/l) 88.4 and 88.6%. Conclusion: A validated platform IA is sufficient to detect subnormal testosterone concentrations in the diagnosis of male hypogonadism. The IA used for E-2 measurements showed poor correlation with MS and may only be suitable for the detection of high E-2 in men.
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| 2. |
- Lee, David M., et al.
(författare)
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Association of hypogonadism with vitamin D status: the European Male Ageing Study
- 2012
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Ingår i: European Journal of Endocrinology. - 1479-683X. ; 166:1, s. 77-85
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Interrelationships between hormones of the hypothalamic-pituitary-testicular (HPT) axis, hypogonadism, vitamin D and seasonality remain poorly defined. We investigated whether HPT axis hormones and hypogonadism are associated with serum levels of 25-hydroxyvitamin D (25(OH)D) in men. Design and methods: Cross-sectional survey of 3369 community-dwelling men aged 40-79 years in eight European centres. Testosterone (T), oestradiol (E(2)) and dihydrotestosterone were measured by gas chromatography-mass spectrometry; LH, FSH, sex hormone binding globulin (SHBG), 25(OH)D and parathyroid hormone by immunoassay. Free T was calculated from total T, SHBG and albumin. Gonadal status was categorised as eugonadal (normal T/LH), secondary (low T, low/normal LH), primary (low T, elevated LH) and compensated (normal T, elevated LH) hypogonadism. Associations of HPT axis hormones with 25(OH)D were examined using linear regression and hypogonadism with vitamin D using multinomial logistic regression. Results: In univariate analyses, free T levels were lower (P=0.02) and E(2) and LH levels were higher (P<0.05) in men with vitamin D deficiency (25(OH)D <50 nmol/l). 25(OH)D was positively associated with total and free T and negatively with E(2) and LH in age- and centre-adjusted linear regressions. After adjusting for health and lifestyle factors, no significant associations were observed between 25(OH)D and individual hormones of the HPT axis. However, vitamin D deficiency was significantly associated with compensated (relative risk ratio (RRR)=1.52, P=0.03) and secondary hypogonadism (RRR=1.16, P=0.05). Seasonal variation was only observed for 25(OH)D (P<0.001). Conclusions: Secondary and compensated hypogonadism were associated with vitamin D deficiency and the clinical significance of this relationship warrants further investigation.
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| 3. |
- Tajar, Abdelouahid, et al.
(författare)
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Characteristics of Androgen Deficiency in Late-Onset Hypogonadism: Results from the European Male Aging Study (EMAS).
- 2012
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 97:5, s. 1508-1516
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Tidskriftsartikel (refereegranskat)abstract
- Context:Late-onset hypogonadism (LOH) has been defined as a syndrome in middle-aged and elderly men reporting symptoms in the presence of low testosterone (T). Objective:The objective of the study was to seek objective biochemical and end-organ evidence of androgen deficiency in men classified as having LOH according to our previously published criteria. Design, Setting, and Participants:The design of the study included cross-sectional data from the European Male Aging Study on 2966 community-dwelling men aged 40-79 years in eight European countries. Main Outcome Measure(s):Waist circumference, body mass index, muscle mass, estimated heel bone mineral density (eBMD), hemoglobin, insulin sensitivity, physical activity, metabolic syndrome, insulin resistance index, and cardiovascular disease were measured. Results:Sixty-three men (2.1%) were classified as having LOH: 36 moderate and 27 severe. They were older and more obese than eugonadal men and had, in proportion to the graded T deficiency, lower muscle mass, eBMD, and hemoglobin, with poorer general health. Both moderate and severe LOH was associated with lower hemoglobin, mid-upper arm circumference, eBMD, physical function (measured by the Short Form-36 questionnaire), slower gait speed and poorer general health. Only men with severe LOH showed significant associations with larger waist circumference (β= 1.93cm; 0.04-3.81), insulin resistance (β= 2.81; 1.39-4.23), and the metabolic syndrome (odds ratio 9.94; 2.73-36.22) after adjustments for confounders. Men with low testosterone only (irrespective of symptoms) showed lesser magnitudes of association with the same end points. Conclusions:LOH is associated with multiple end-organ deficits compatible with androgen deficiency. These data support the existence of a syndrome of LOH in only a minority of aging men, especially those with T below 8 nmol/liter.
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