Longitudinal Associations Between Changes in Body Mass Index and Erectile Dysfunction

Brazilian men who became newly obese had 2.46× the odds of persistent ED vs. stable healthy-weight men; those already obese had 1.73×

Journal: Journal of Sexual Medicine | Published: 2026-04-09 | Type: Longitudinal cohort study | PMID: 42018784 Authors: Pitta RM, Kaufmann OG, de Victo ER, Cucato GG, de Lima Queiroga L, Wolosker N (Faculdade Israelita de Ciências da Saúde Albert Einstein, São Paulo; Northumbria University, UK) Funding/COI: São Paulo Research Foundation; COI not reported

Summary

This longitudinal cohort tracked 924 Brazilian men aged ≥40 — all with ED at baseline — through repeat health evaluations spanning 2008–2022, with follow-up visits 300–800 days apart. The central finding: men who transitioned into obesity showed higher odds of persistent ED than those who had been obese all along, suggesting the change in BMI trajectory carries independent risk beyond static weight status. At follow-up, 44.3% of men no longer reported ED — a recovery rate the paper doesn't adequately explain.

Claims

• Men who became obese during follow-up: OR 2.46 (95% CI 1.15–5.27, P = 0.021) for ED vs. men who remained healthy weight
• Men who remained obese: OR 1.73 (95% CI 1.22–2.45, P = 0.002) for ED vs. remained healthy weight
• BMI trajectory groups: 70.1% remained healthy, 21.9% remained obese, 4.1% became obese, 3.9% became healthy
• At follow-up: 44.3% no ED, 32.0% mild, 2.5% mild-to-moderate, 16.0% moderate, 5.2% severe
• Associations held after adjusting for age, comorbidities, and lifestyle factors

Study Quality

The longitudinal design is an upgrade over the cross-sectional studies that dominate this literature, and the sample size (n = 924) is reasonable for a cohort study. Using the IIEF-5 at both timepoints gives a validated, consistent outcome measure. The hierarchical logistic regression adjusted for a credible set of confounders — demographics, comorbidities, behavioral variables — and the 14-year data collection window at a single center provides some depth.

The critical methodological hole: all 924 men had ED at baseline. This is not a study of who develops ED — it's a study of whose ED persists or improves. That's a narrower and different question than the framing implies, and the conclusions should be read accordingly. Additionally, follow-up windows varied from 300 to 800 days, introducing meaningful noise in trajectory classification.

Red Flags

• Tiny trajectory subgroups: "Became obese" = ~38 men (4.1% of 924); "became healthy" = ~36 men. The OR of 2.46 rests on approximately 38 participants — the wide confidence interval (1.15–5.27) makes this explicit
• Selected sample: Every participant had ED at enrollment. Findings cannot be generalized to men without ED at baseline, limiting inference about ED incidence
• No testosterone data: Hypogonadism is a major confounder for both obesity and ED; its absence is a stated limitation and a genuine one
• Self-reported lifestyle variables: Physical activity, diet, and alcohol intake are all subject to recall bias
• COI not reported: Disclosure is absent; the funding source (FAPESP) is government-linked, which is reassuring but doesn't substitute for author-level disclosure
• The 44.3% ED resolution rate: Nearly half the cohort lost their ED diagnosis at follow-up. This extraordinary improvement rate gets no mechanistic discussion — regression to the mean, spontaneous recovery, and differential dropout are plausible competing explanations

Strengths

• Longitudinal design captures within-person change rather than a single snapshot
• IIEF-5 applied consistently at baseline and follow-up
• Brazilian population adds geographic diversity to a literature dominated by North American and European cohorts
• Long study period (2008–2022) and multi-decade follow-up infrastructure
• Adjusted analysis controlled for age, comorbidities, and behavioral variables

Verdict

The trajectory framing is genuinely more useful than a cross-sectional BMI snapshot, and the finding that newly acquired obesity carries higher ED odds than longstanding obesity (2.46 vs. 1.73) is interesting — if the numbers hold up. They might not: the "became obese" subgroup is roughly 38 men, and the confidence interval nearly grazes 1.0. The "remained obese" estimate is far more trustworthy. Bigger conceptual problem: this study only tells you about ED persistence in men who already had ED, which the title and conclusion don't adequately flag. Treat the "became obese" finding as hypothesis-generating, not settled.