Hair Loss After Metabolic and Bariatric Surgery: a Systematic Review and Meta-analysis

source extracted confidence: high 2026-04-09
#alopecia #bariatric-surgery #female #humans #obesity-morbid

Hair Loss After Metabolic and Bariatric Surgery: a Systematic Review and Meta-analysis

Zhang et al., 2021 | Obes Surg | Meta Analysis

Citation

Zhang Wen, Fan Meiling, ... Yang Wah. Hair Loss After Metabolic and Bariatric Surgery: a Systematic Review and Meta-analysis. Obes Surg. 2021-Jun;31(6):2649-2659. doi:10.1007/s11695-021-05311-2

Abstract

BACKGROUND: Hair loss is a common complication after metabolic and bariatric surgery (MBS). There is a lack of published systematic review in the scientific literature on this topic. The aim of this study was to perform a systematic review and meta-analysis on hair loss after MBS in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. METHODS: PubMed, CINAHL, EMBASE, Web of Science, SCOPUS, and four Chinese databases were searched. Data were pooled using Review Manager 5.3 and Stata 12.0, and subgroups were performed if necessary and feasible. RESULTS: A total of 18 studies (n = 2538) were included. The pooled results showed that the incidence of hair loss after MBS was 57% (95% CI 42-71%). It decreased with longer follow-up times. Hair loss was significantly more common in younger (mean difference (MD), - 2.45; 95% CI, - 4.26 to - 0.64; p = 0.008) women (OR, 3.87; 95% CI, 0.59 to 17.59; p = 0.08). Serum zinc (standardized mean difference (SMD), - 1.13; 95% CI, - 2.27 to 0.01, p = 0.05), folic acid (SMD = - 0.88, 95% CI - 1.29 to - 0.46, p < 0.0001), and ferritin levels (SMD, - 0.22; 95% CI, - 0.38 to - 0.05; p = 0.01), but not serum iron and vitamin B12, were associated with hair loss following MBS. CONCLUSIONS: Hair loss is common after MBS especially in younger women, and those with low serum levels of zinc, folic acid, and ferritin. Prospective studies on larger cohorts are needed.

Key Findings

A total of 18 studies (n = 2538) were included. The pooled results showed that the incidence of hair loss after MBS was 57% (95% CI 42-71%). It decreased with longer follow-up times. Hair loss was significantly more common in younger (mean difference (MD), - 2.45; 95% CI, - 4.26 to - 0.64; p = 0.008) women (OR, 3.87; 95% CI, 0.59 to 17.59; p = 0.08). Serum zinc (standardized mean difference (SMD), - 1.13; 95% CI, - 2.27 to 0.01, p = 0.05), folic acid (SMD = - 0.88, 95% CI - 1.29 to - 0.46, p < 0

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 2538
Age Range See abstract
Condition See abstract

MeSH Terms

  • Alopecia
  • Bariatric Surgery
  • Female
  • Humans
  • Obesity, Morbid
  • Prospective Studies
  • Vitamin B 12

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Systematic Review
  • Vertical: vitamin-b12

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09