Dilated cardiomyopathy is diagnosed twice as often in males than in females. A new three-part study, which included a systematic literature review, meta-analysis and a population study, examined the reasons behind this.
The researchers considered whether dilated cardiomyopathy is more common in one sex than the other, how genetics contribute to this difference, and whether diagnostic practices account for any differences between the sexes.
The findings revealed that the sex ratio disparity of diagnoses arose from a combination of underdiagnosis in women and a greater susceptibility for men, driven by additional genetic or environmental factors that increase disease manifestation in genetically predisposed individuals.
The researchers examined multiple data sources to identify potential biases or biological influences on disease prevalence. A literature search identified existing studies with sex ratio data for patients with dilated cardiomyopathy.
Meta-analysis and metaregression analysis were used to compare the proportion of female participants in an overall dilated cardiomyopathy cohort and the following subtypes: all genetic, individual selected genes (TTN and LMNA), and gene-elusive.
In addition, population dilated cardiomyopathy sex ratios were analysed from diagnostic codes and compared with those obtained from sex-specific means, such as International Classification of Diseases-coded, novel imaging-first, and genotype-first data from the UK Biobank imaging cohort.
Considering 99 studies, the researchers analysed data from 37,525 participants with dilated cardiomyopathy, 30% of whom were female, giving a male-to-female ratio of 2.38:1.
Within subgroup cohorts, similar patterns emerged. In patients with identified dilated cardiomyopathy genetic variants, the male-to-female ratio was 2.22:1. For patients with no genetic variants, the male-to-female ratio was 2.29:1.
The UK Biobank data showed a 4.5:1 ratio of men to women with dilated cardiomyopathy. However, when the researchers used sex-specific diagnostic techniques, such as imaging-first and genotype-first diagnostic approaches, the ratios changed to 1.7:1 and 2.3:1, respectively.
The results showed that the condition is more common in men, and, even after adjusting diagnostic criteria to account for sex, the male predominance in the development of the disease persists.
The researchers suggested that future work should evaluate sex-specific dilated cardiomyopathy diagnostic criteria and examine the genetic, reproductive and environmental factors contributing to differences in disease risk in male and female patients.
Reference
Bergen, N et al. Systematic Review, Meta-Analysis, and Population Study to Determine the Biologic Sex Ratio in Dilated Cardiomyopathy. Circulation 2025; Feb 03: DOI: 10.1161/CIRCULATIONAHA.124.070872.
