Summary
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1 Sample Definition And Size
The study analyzed data from the 2011–2016 National Health and Nutrition Examination Surveys (NHANES), including 1,486 men aged 20 to 44 years. Exclusions were men on hormonal medications, with a history of testicular cancer or orchiectomy, and those with afternoon or evening laboratory values. ([pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/36282060/?utm_source=openai))
2 Study Type
Observational, cross-sectional analysis of a nationally representative survey (NHANES) to derive age-specific normative testosterone levels and cutoffs. ([pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/36282060/?utm_source=openai))
3 Conflicts Of Interest
No conflicts of interest or sources of bias were declared in the abstract or available metadata. ([pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/36282060/?utm_source=openai))
4 Results Summary
Age-specific middle tertile (normal) total testosterone ranges and corresponding low-testosterone cutoffs were: 20–24 years: 409–558 ng/dL (cutoff 409 ng/dL); 25–29 years: 413–575 ng/dL (cutoff 413 ng/dL); 30–34 years: 359–498 ng/dL (cutoff 359 ng/dL); 35–39 years: 352–478 ng/dL (cutoff 352 ng/dL); 40–44 years: 350–473 ng/dL (cutoff 350 ng/dL). These cutoffs are substantially higher than the traditional 300 ng/dL threshold. ([pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/36282060/?utm_source=openai))