Effects of the body mass index of males on hormone levels, sperm and embryo parameters, and clinical outcomes in non-obstructive azoospermia: a systematic review and meta-analysis
Bibliographic record
Abstract
Background: Research has shown that the body mass index (BMI) is not correlated with sperm retrieval outcomes, while serum testosterone and gonadotropins are related to the BMI in non-obstructive azoospermia (NOA). Previously, no comprehensive assessment had been conducted on the effect of the BMI of males in NOA. This study sought to comprehensively evaluate the effects of the BMI of males on hormone levels, sperm and embryo parameters, and clinical outcomes in NOA. Methods: The PubMed, Embase, Cochrane Library, and Web of Science databases were searched to retrieved relevant articles published up to May 27, 2022. Articles which examined patients with NOA (population), included patients with a BMI ≥25 kg/m 2 (intervention) versus patients with a BMI <25 kg/m 2 (comparator), assessed reproductive hormones, sperm and embryo parameters, and clinical outcomes (outcome), and were cohort studies (study design) were included. The quality of the included studies was assessed by the Newcastle-Ottawa Scale (NOS). A sensitivity analysis was conducted for all the outcomes. Results: A total of 12 studies comprising 2,994 NOA patients were included. Patients with a BMI ≥25 kg/m 2 had lower follicle-stimulating hormone (FSH) [pooled weighted mean difference (WMD): –0.67, 95% confidence interval (CI): –0.94 to –0.41, P<0.001] and total testosterone (TT) (pooled WMD: –1.35, 95% CI: –2.10 to –0.60, P<0.001) levels than those with a normal weight (BMI <25 kg/m 2 ). The testicular volume of the BMI ≥25 kg/m 2 group was larger than that of the normal weight group (pooled WMD: 0.26, 95% CI: 0.09 to 0.44, P=0.003). The average BMI of the group with successful sperm extraction was lower than that of the group with failed sperm extraction (pooled WMD: –0.97, 95% CI: –1.89 to –0.04, P=0.041). The live-birth rate of the BMI ≥25 kg/m 2 group was lower than that of the normal weight group [pooled relative risk (RR) =0.88, 95% CI: 0.78 to 0.99, P=0.031]. Conclusions: The BMI of the males was an important factor affecting the FSH and TT levels, testicular volume, sperm retrieval success, and live-birth rate in NOA. Weight management may benefit NOA patients.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.007 | 0.018 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.012 | 0.020 |
| Bibliometrics | 0.005 | 0.005 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".