Soon Ki Kim

Obesity in Korean Men: Results from the Fourth through Sixth Korean National Health and Nutrition Examination Surveys (2007∼2014)

Purpose Obesity is related to many diseases, including urological conditions. We investigated the prevalence, risk factors, and treatment of male obesity. Materials and Methods This study included 17,485 men older than 20 years of age who participated in the fourth, fifth, and sixth administrations of the Korean National Health and Nutrition Examination Survey. Two main cutoff points for obesity were defined: a body mass index (BMI) ≥25 kg/m2 and a BMI≥30 kg/m2. Additionally, we defined obesity requiring pharmacotherapy as the presence of a BMI≥30 kg/m2 or a BMI≥27 kg/m2 co-occurring with at least one associated comorbid medical condition, such as hypertension, dyslipidemia, or diabetes. Results The prevalence rates of a BMI≥25 kg/m2, a BMI≥30 kg/m2, and obesity requiring pharmacotherapy were 35.7%, 3.4%, and 10.5%, respectively. The prevalence of obesity increased over time for all definitions of obesity. The prevalence of obesity requiring pharmacotherapy was highest in Jeju (12.5%) and lowest in Gangwon-do (7.7%). Having a higher income, being a non-manual worker, and having completed a high level of education were significantly related to obesity requiring pharmacotherapy. More than 70% of patients with obesity requiring pharmacotherapy reported taking diet pills, eating functional foods, or consuming a one-food diet for weight reduction, but only 13.9% reported exercising for this purpose. Conclusions Male obesity is a common condition, the prevalence of which is expected to continue to increase over time. A better strategy is required to manage male obesity in Korea.

Phosphorus as predictive factor for erectile dysfunction in middle aged men: A cross sectional study in Korea

Purpose High serum inorganic phosphorus level is related with atherosclerosis and an elevated risk of cardiovascular disease. At the same time, the association of phosphorus with erectile dysfunction (ED) is not well reported. We studied the effect of serum phosphorus on ED and the relationship with other clinical variables. Materials and Methods From March to September 2013, 1,899 police men aged 40 to 59 years who entered in a prostate health screening were targeted. All subjects underwent a clinical checking using the International Index of Erectile Function-5 (IIEF-5) questionnaire translated into Korean. Serum prostate-specific antigen (PSA), testosterone, inorganic phosphorus, body mass index, metabolic syndrome (MetS), and prostate ultrasound were also examined. Results Serum inorganic phosphorus (r=–0.108, p<0.001) had the highest correlation coefficient with IIEF-5 score other than age, followed by prostate volume (PV) (r=–0.065, P<0.001). Using logistic regression analysis, age, phosphorus, and MetS were predictive factors for moderate to severe ED in univariate analysis. PSA, testosterone, body mass index, and PV could not predict ED. Age, MetS, and phosphorus were independent predictive factors of moderate to severe ED (p<0.001; odds ratio [OR], 1.119; 95% confidence interval [CI] 1.086–1.153; p=0.048; OR, 1.283; 95% CI, 1.003–1.641; and p=0.048; OR, 1.101; 95% CI, 1.076–1.131) in the multivariate analysis. Conclusions In our study, phosphorus level is related with ED. Phosphorus is a significant predictor of ED and a strong factor that can be modified in the middle-age. Controlling phosphorus in men may have a particular meaning of preventing the occurrence of ED.

The authors reply: Phosphorus as predictive factor for erectile dysfunction in middle aged men: A cross sectional study in Korea

To the editor: Our study was cross-sectional study as you say. As we mentioned in the limitations of this study, the cross-sectional design rules out the evaluation of causality and may have issues of temporality among the variables. We agree with your opinion. Our conclusions are somewhat exaggerated. Now, we re-announce to our readers that our research is about the potential relevancy of phosphorus and erectile dysfunction rather than prediction. We know that internal validity is best estimated with bootstrapping and split-validation, which can provide stable estimates with low bias. At this point, however, we had too few variables. Especially, we did not have information about serum free or calculated testosterone, insulin-like growth factor-1, several cytokines, or C-reactive protein, which are considered to be important for erectile dysfunction. Thus, we agree that there is a real difficulty in proper model development. In addition, external validity must typically be studied in independent validation samples with patients from a different but “plausibly related” population [1]. However, we have yet to find a suitable comparable group. The authors reply: Phosphorus as predictive factor for erectile dysfunction in middle aged men: A cross sectional study in Korea