Currently ongoing COVID-19 pandemic, has led to an increase in the number of CT scans performed due to a presumed diagnosis of pneumonia worldwide (8). This has caused various diseases and/or medical conditions to be noticed incidentally in CT examinations (15, 16, 17). On the other hand, this situation could be seen as an opportunity to retrospectively examine the relationships between various parameters through these CT scans with more objective measurements. In the present study, we investigated the correlations between hepatic steatosis as determined on CT images of male patients who underwent chest imaging due to suspected COVID-19, gynecomastia and epicardial fat thickness.
In the present study, the mean age of patients with gynecomastia was found as 47.21 years. Kim et al. reported the mean age as 56.99 years in 650 male patients with gynecomastia (9). Aslan et al. reported the most common age group with gynecomastia as 30-39 years (8). This range was 36-55 years in our study, although age ranges were different between the two studies general ranges were similar. Similar to our study, Aslan et al. examined CT images of male patients who were admitted during the coronavirus disease-2019 (COVID-19) pandemic to determine the prevalence of gynecomastia. The authors found significant correlations between age, right breast glandular tissue diameter (r=.235, p<0.001) and left breast glandular tissue diameter (r=.219, p<0.001) (8). In the present study, age was found to be positively correlated with the left subareolar glandular tissue diameter (r=.113, p=0.05), and right retroareolar fatty tissue diameter (r=.116, p=0.04) (Figure 2). These findings suggest a relationship between age and gynecomastia, possibly due to decreased testosterone levels with ageing.
Studies investigating the relationship between liver disease and gynecomastia have reported conflicting results. Hepatic steatosis has been associated with low testosterone and high estrogen levels, diminished libido and gynecomastia, which is the most common benign condition characterized by enlargement of the male breast (18). Furthermore, there are studies reporting that testosterone administration to cyrrhotic patients has decreased the prevalence of gynecomastia (19). However, others could not find such a relationship and proposed that breast tissue sensitivity to a raised ratio of estrogen/testosterone is highly variable (11). In the present study, the left subareolar tissue thickness and the right retroareolar fatty tissue thickness that are used to indicate the presence of gynecomastia were found to be significantly correlated with liver density in negative direction (r=-.137, p<0.001; r=-.172, p<0.001; respectively) suggesting a relationship between hepatic steatosis and gynecomastia. Nevertheless, there is no sufficient data in the literature to draw a definitive conclusion on this issue and mechanisms of such a potential correlation are yet to be clarified.
Epicardial fat accounts for 20% of heart weight and constitutes 80% of the heart’s surface. Although it is a relatively neglected component of the heart, it has been proposed as a marker of cardiovascular risk (20, 21). On the other hand, previous studies have reported the relationship of epicardial fat thickness with various diseases and medical conditions. Shemirani et al. reported a correlation between epicardial fat thickness and the severity of coronary artery disease (22). Metwally et al. observed elevated epicardial fat thickness in pediatric patients with congenital adrenal hyperplasia (23). According to Petta et al., in patients with non-alcoholic fatty liver disease (NAFLD), a higher epicardial fat thickness is associated with the severity of the disease (13). Iacobellis et al. reported that epicardial fat thickness is a good indicator of hepatic steatosis in obese patients (24). Results of our study indicated a strong correlation between epicardial fat thickness and liver density, which is used to determine the presence of hepatic steatosis (r=.178, p<0.01).
Although epicardial fat thickness is known to be closely associated with fat deposition, no study could be found to investigate its correlation with fat proliferation in men's breasts, namely gynecomastia. In the present study, epicardial fat thickness was statistically significantly correlated with right subareolar tissue thickness (r=.085, p=0.037), left subareolar tissue thickness (r=.101, p=0.014) and right retroareolar fatty tissue thickness (r=.148, p<0.001). However, the mechanisms underlying these correlations are yet to be clarified.
Study Limitations
Major limitations of this study include its retrospective design and being performed in a single center. In addition, the same correlations could be investigated between obese and non-obese patients as epicardial fat thickness is closely associated with obesity. Finally, our results on the correlation between epicardial fat thickness and gynecomastia could not be compared due to the lack of similar studies. On the other hand, the number of our patients is relatively large and we examined the associations between hepatic steatosis, gynecomastia and epicardial fat thickness together, as the first time in the literature.