Written by Harold Oster, MD. Results suggest that elevated urinary cadmium levels are associated with an increased prevalence of endometriosis.
Endometriosis, the development of endometrial tissue outside of the uterine cavity, is a painful condition affecting 10-15% of women of reproductive age. Excess estrogen exposure over a long duration is a contributing factor in the pathogenesis of endometriosis1. Cadmium, a heavy metal, is an environmental pollutant of mining and other industries and enters the food chain primarily through its contamination of food and water. Cadmium has been linked to cardiovascular disease, cancer, and due to its estrogenic effect, reproductive disorders2.
Mandy S. Hall et al. studied the association between urinary cadmium levels and the prevalence of endometriosis among participants in the National Health and Nutrition Examination Survey (NHANES), a population-based cross-sectional study conducted by the National Center for Health Statistics at the Centers for Disease Control and Prevention. From 1999 to 2006, NHANES gathered data from 41,474 participants by questionnaire, physical examination, and samples of blood and urine. Based on defined inclusion criteria, Hall et al. used data from 1750 female NHANES participants, aged 20-54 years. Urine samples were tested for cadmium concentration, a known marker of long-term cadmium exposure3. Participants were placed into quartiles based on the level of urinary cadmium after adjustment for dilution, with the first quartile being defined as having the lowest level. A history of endometriosis was determined by questionnaire. Possible covariates were ascertained, including age at diagnosis of endometriosis, body mass index, gynecologic history, and lifestyle factors.
The authors noted the following:
- The prevalence of endometriosis was 9.4%
- After adjustment for covariables, the prevalence of endometriosis in the second and third cadmium level quartiles was twice as high as the prevalence in the first quartile.
- The prevalence of endometriosis in quartile four was 60% higher than in quartile one.
The results of the study suggest that elevated urinary cadmium levels are associated with an increased prevalence of endometriosis. Limitations of the study include possible confounding by gynecologic conditions associated with endometriosis that may also be linked to cadmium exposure, possible residual confounding by lifestyle factors, and reliance on self-reporting for the diagnosis of endometriosis.
Source: Hall, Mandy S., Nicole M. Talge, and Kristen Upson. “Urinary cadmium and endometriosis prevalence in a US nationally representative sample: results from NHANES 1999–2006.” Human Reproduction (2023): dead117.
© The Author(s) 2023. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
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Posted August 28, 2023.
Harold Oster, MD graduated from medical school in Miami, Florida in 1992 and moved to Minnesota in 2004. After more than 25 years of practicing Internal Medicine, he recently retired. Dr. Oster is especially interested in nutrition, weight management, and disease prevention. Visit his website at haroldoster.com.
References:
- Chauhan S, More A, Chauhan V, Kathane A. Endometriosis: A Review of Clinical Diagnosis, Treatment, and Pathogenesis. Cureus. Sep 2022;14(9):e28864. doi:10.7759/cureus.28864
- Genchi G, Sinicropi MS, Lauria G, Carocci A, Catalano A. The Effects of Cadmium Toxicity. Int J Environ Res Public Health. May 26 2020;17(11)doi:10.3390/ijerph17113782
- Vacchi-Suzzi C, Kruse D, Harrington J, Levine K, Meliker JR. Is Urinary Cadmium a Biomarker of Long-term Exposure in Humans? A Review. Curr Environ Health Rep. Dec 2016;3(4):450-458. doi:10.1007/s40572-016-0107-y
