Abstract
We aimed to assess the relationship between lifestyle-related variables, metabolic syndrome, and lower urinary tract symptoms (LUTS) in men ≥ 40 years. We also assessed the impact of these variables on quality of life. From 2014 to 2020, 5355 men who underwent health check-ups with I-PSS questionnaires at our institute were included in the analysis. The impact of LUTS on sleep disorders and moderate to severe degrees of stress were assessed. Multivariate analysis was performed to determine the variables associated with LUTS and prostate volume. Moderate and severe LUTS were present in 1317 (24.6%) and 211 (3.9%) men, respectively. Moderate and severe LUTS were significantly associated with the presence of sleep disorders and stress. On multivariable analysis, age, amount of life-long smoking, marital status, income, job, and decreased HDL-cholesterol were associated with the presence of moderate to severe LUTS. Although older age and the amount of life-long smoking was associated with both voiding and storage sub-score, socioeconomic status, including marital status and income were only associated with storage sub-score. In men ≥ 40 years, stable socioeconomic status, in addition to older age, and life-long smoking amount are associated with the presence of moderate to severe LUTS, which worsens sleep quality and stress level, by worsen storage sub-score.
Subject terms: Urology, Prostate, Metabolic disorders
Introduction
Recently, as life expectancy has increased, interest in the quality of life (QoL) in elderly individuals is rapidly increasing. In elderly men, lower urinary symptoms (LUTS) were reported to significantly worsen QoL1,2. However, currently, no clear strategies to prevent the development of LUTS have been developed, despite more than 40% of men suffering from at least one LUTS3. When we consider the medical costs for relieving LUTS in elderly men4 and its impact on individual QoL, the development of strategies to prevent LUTS in men is urgently needed.
Maintaining a positive health status is thought to be important for improving QoL, and preventing metabolic syndrome (MetS) is one of the most important concepts for maintaining a positive health status, especially when a person gets older5–7. Traditionally, MetS has been regarded as an important risk factor for cardiovascular or cerebrovascular events5. However, recently, the relationship between MetS and other chronic diseases has been increasingly reported6,7, and LUTS and benign prostatic hyperplasia (BPH) in men have also been reported to be associated with MetS and its components8.
In our previous studies, we identified that MetS and its components, especially decreased high-density lipoprotein (HDL) cholesterol, are related to the presence of prostatic disease, including BPH and prostate cancer, using a large national health insurance database cohort9,10. However, because the severity of LUTS has not been routinely measured as a health check-up in the normal population, there are only a few studies that address the impact of MetS and its components on the severity of LUTS, and these studies did not show consistent results11–14. This might be due to the complex correlation between lifestyle variables, MetS, and LUTS; to elucidate the real impacts of MetS and lifestyle factors on LUTS, thorough analysis using a large database with detailed information is needed.
In our institute, the International Prostate Symptom Score (I-PSS) questionnaires were routinely administered in men who visited the health check-up center. In this study, we aimed to assess the relationship between MetS/lifestyle-related variables and LUTS using these databases, in addition to its impact on QoL. We evaluated the impacts of LUTS on sleep quality and stress to address the effects of improving LUTS on QoL. In addition, we assessed the association between the severity of LUTS and metabolic components and lifestyle-related variables to elucidate the prevention strategies for moderate to severe LUTS to improve QoL by lifestyle modification. We also assessed the impact of these variables on prostate volume to demonstrate the possible reasons for moderate to severe LUTS in these men.
Results
Among the study population, moderate and severe LUTS were present in 1317 (24.6%) and 211 (3.9%) men, respectively (Table 1). In addition to age, obesity, marital status, job, monthly income, life-long smoking amount, physical activity, and decreased HDL-cholesterol levels were significantly associated with the severity of LUTS. The presence of sleep disorders and moderate to severe stress were also significantly higher as LUTS severity increased. The PSA level and prostate volume were higher in men with severe LUTS.
Table 1.
Baseline characteristics according to severity of LUTS.
| None to mild | Moderate | Severe | P | |
|---|---|---|---|---|
| N (%) | 3827 (71.5) | 1317 (24.6) | 211 (3.9) | |
| Age, years, mean ± SD | 52.4 ± 8.8 | 56.5 ± 9.4 | 59.0 ± 9.7 | < 0.001 |
| Body weight, kg, mean ± SD | 72.4 ± 10.4 | 70.7 ± 9.9 | 69.3 ± 10.4 | < 0.001 |
| BMI, kg/m2, mean ± SD | 24.7 ± 2.9 | 24.4 ± 2.9 | 24.2 ± 3.1 | < 0.001 |
| Waist circumference, cm, mean ± SD | 87.1 ± 8.2 | 87.0 ± 8.1 | 87.3 ± 8.6 | 0.858 |
| Marital status, n (%) | < 0.001 | |||
| Yes | 3449 (90.1) | 1161 (88.2) | 164 (77.7) | |
| Others | 354 (9.3) | 140 (10.6) | 44 (20.9) | |
| Unknown | 24 (0.6) | 16 (1.2) | 3 (1.4) | |
| Job, n (%) | < 0.001 | |||
| Office-worker | 2678 (70.0) | 752 (57.1) | 90 (42.7) | |
| Others | 1028 (26.9) | 504 (38.3) | 103 (48.8) | |
| Unknown | 121 (2.3) | 61 (4.6) | 18 (8.5) | |
| Monthly income, n (%) | < 0.001 | |||
| < $2684 | 3221 (84.2) | 985 (74.8) | 127 (60.2) | |
| ≥ $2684 | 455 (11.9) | 250 (19.0) | 67 (31.8) | |
| Unknown | 151 (3.9) | 82 (6.2) | 17 (8.1) | |
| Current smoker, n (%) | 1169 (30.5) | 380 (28.9) | 68 (32.2) | 0.414 |
| Amount of smoking, PY, mean ± SD | 11.6 ± 13.7 | 14.8 ± 16.7 | 19.0 ± 19.5 | < 0.001 |
| Drinking, g/week, mean ± SD | 0.310 | |||
| 0 g/week | 997 (26.1) | 354 (26.9) | 60 (28.4) | |
| > 0 and < 100 g/week | 875 (22.9) | 291 (22.1) | 43 (20.4) | |
| ≥ 100 g/week | 1876 (49.0) | 649 (49.3) | 99 (46.9) | |
| Unknown | 79 (2.1) | 23 (1.7) | 9 (4.3) | |
| ln (MET), mean ± SD | 5.6 ± 3.0 | 5.6 ± 3.0 | 3.0 ± 5.0 | 0.015 |
| Metabolic syndrome, n (%) | 1395 (36.5) | 516 (39.2) | 85 (40.3) | 0.137 |
| Central obesity, n (%) | 1419 (37.1) | 468 (35.5) | 80 (37.9) | 0.567 |
| Hypertension, n (%) | 2355 (61.5) | 800 (60.7) | 132 (62.6) | 0.824 |
| Diabetes, n (%) | 1370 (35.8) | 502 (38.1) | 90 (42.7) | 0.058 |
| Triglyceridemia, n (%) | 1521 (39.7) | 567 (43.1) | 86 (40.8) | 0.108 |
| Decreased HDL, n (%) | 1126 (29.4) | 476 (36.1) | 69 (32.7) | < 0.001 |
| Sleep disorder, n (%) | 1725 (45.4) | 802 (61.6) | 154 (74.4) | < 0.001 |
| Stress, n (%) | 1160 (30.3) | 541 (41.1) | 115 (54.5) | < 0.001 |
| PSA, mL, mean ± SD | 1.6 ± 1.6 | 1.9 ± 5.1 | 2.6 ± 4.4 | < 0.001 |
| Prostate size, cc, mean ± SD (n = 827) | 25.2 ± 7.8 | 25.5 ± 7.8 | 28.9 ± 13.1 | 0.001 |
Sleep disorders were significantly higher in men with moderate and severe LUTS. Although all components of sleep disorder were significantly related to the severity of LUTS, among components of sleep disorder, sleep disturbance (r = 0.322, p < 0.001) was most closely associated with the severity of LUTS, followed by subjective sleep quality (r = 0.252, p < 0.001), sleep latency (r = 0.184, p < 0.001), and daytime dysfunction (r = 0.161, p < 0.001). In multivariate analysis, moderate and severe LUTS were significantly associated with the presence of sleep disorder, in addition to older age, current smoker, increased amount of smoking, marital status, alcohol consumption ≥ 100 g/week, and decreased physical activity (Table 2). Moreover, moderate and severe LUTS were associated with moderate to severe stress, in addition older age, current smoking, increased amount of smoking, marital status, low income, and decreased physical activity.
Table 2.
Variables associated with quality of life.
| Multivariable | ||
|---|---|---|
| OR (95% CI) | P | |
| (1) Variables associated with the presence of sleep disorder | ||
| Age, years (continuous) | 0.983 (0.976–0.990) | < 0.001 |
| Current smoker (yes vs. no) | 1.329 (1.164–1.519) | < 0.001 |
| Amount of smoking, PY (continuous) | 1.009 (1.004–1.014) | 0.001 |
| Marital status, n (%) | ||
| Yes | Reference | |
| Others | 1.668 (1.372–2.026) | < 0.001 |
| Unknown | 0.940 (0.487–1.816) | 0.854 |
| Job, n (%) | ||
| Office-worker | Reference | |
| Others | 1.043 (0.913–1.193) | 0.534 |
| Unknown | 1.560 (1.127–2.160) | 0.007 |
| Alcohol consumption, n (%) | ||
| 0 g/week | Reference | |
| > 0 and < 100 g/week | 0.965 (0.823–1.132) | 0.661 |
| ≥ 100 g/week | 1.288 (1.123–1.477) | < 0.001 |
| Unknown | 0.875 (0.583–1.313) | 0.518 |
| ln (MET) (continuous) | 0.979 (0.961-.0998) | 0.029 |
| IPSS severity, n (%) | ||
| Normal to mild | Reference | |
| Moderate | 2.012 (1.761–2.300) | < 0.001 |
| Severe | 3.422 (2.467–4.747) | < 0.001 |
| (2) Variables associated with the presence of moderate to severe stress | ||
| Age, years (continuous) | 0.957 (0.949–0.964) | < 0.001 |
| Current smoker (yes vs. no) | 1.371 (1.192–1.576) | < 0.001 |
| Amount of smoking, PY (continuous) | 1.006 (1.002–1.011) | 0.005 |
| Marital status, n (%) | ||
| Yes | Reference | |
| Others | 1.670 (1.374–2.030) | < 0.001 |
| Unknown | 0.961 (0.477–1.936) | 0.911 |
| Income, n (%) | ||
| ≥ $2684 | Reference | |
| < $2684 | 1.281 (1.056–1.555) | 0.012 |
| Unknown | 0.995 (0.722–1.371) | 0.974 |
| ln (MET) (continuous) | 0.982 (0.963–1.002) | 0.074 |
| IPSS severity, n (%) | ||
| Normal to mild | Reference | |
| Moderate | 1.861 (1.622–2.136) | < 0.001 |
| Severe | 3.196 (2.374–4.302) | < 0.001 |
On multivariable analysis, older age, increased amount of life-long smoking, marital status, low income, non-office workers, and decreased HDL cholesterol levels were significantly associated with the presence of moderate to severe LUTS (Table 3). Older age, marital status, and low income were also significantly associated with the presence of severe LUTS. On multivariable linear regression analysis, older age, increased amount of life-long smoking, and low income was associated with the I-PSS total score (Table 4). Voiding sub-score was associated with older age, increased amount of life-long smoking, and the presence of hypertension. Storage sub-score was associated with older age , increased amount of life-long smoking, marital status, and low income.
Table 3.
Variables associated with the severity of LUTS.
| Moderate to severe LUTS | Severe LUTS | |||||||
|---|---|---|---|---|---|---|---|---|
| Univariate | Multivariable | Univariate | Multivariable | |||||
| OR (95% CI) | P | OR (95% CI) | P | OR (95% CI) | P | OR (95% CI) | P | |
| Age (continuous) | 1.054 (1.047–1.061) | < 0.001 | 1.044 (1.036–1.052) | < 0.001 | 1.062 (1.04–1.076) | < 0.001 | 1.050 (1.034–1.066) | < 0.001 |
| Current smoker | 0.943 (0.828–1.074) | 0.377 | 1.104 (0.822–1.482) | 0.512 | ||||
| Amount of smoking | 1.017 (1.013–1.021) | < 0.001 | 1.011 (1.007–1.015) | < 0.001 | 1.023 (1.016–1.030) | < 0.001 | 1.017 (1.009–1.024) | < 0.001 |
| Marital status, n (%) | ||||||||
| Yes | Reference | Reference | Reference | Reference | ||||
| Others | 1.353 (1.120–1.635) | 0.002 | 1.248 (1.015–1.535) | 0.036 | 2.504 (1.772–3.537) | < 0.001 | 2.062 (1.417–3.000) | < 0.001 |
| Unknown | 2.061 (1.125–3.774) | 0.019 | 1.391 (0.709–2.726) | 0.337 | 2.108 (0.646–6.885) | 0.217 | 1.287 (0.362–4.570) | 0.696 |
| Income | ||||||||
| ≥ $2684 | Reference | Reference | Reference | Reference | ||||
| < $2684 | 2.018 (1.722–2.365) | < 0.001 | 1.224 (1.013–1.479) | 0.036 | 3.147 (2.317–4.276) | < 0.001 | 1.753 (1.243–2.474) | 0.001 |
| Unknown | 1.899 (1.461–2.649) | < 0.001 | 1.241 (0.911–1.690) | 0.171 | 2.416 (1.432–4.077) | 0.001 | 1.445 (0.812–2.571) | 0.211 |
| Job, n (%) | ||||||||
| Office-worker | Reference | Reference | Reference | |||||
| Others | 1.878 (1.654–2.132) | < 0.001 | 1.203 (1.034–1.400) | 0.017 | 2.562 (1.919–3.421) | < 0.001 | ||
| Unknown | 2.077 (1.548–2.786) | < 0.001 | 1.241 (0.911–1.690) | 0.171 | 3.769 (2.224–6.388) | < 0.001 | ||
| Alcohol consumption, n (%) | ||||||||
| 0 g/week | Reference | Reference | ||||||
| > 0 and < 100 g/week | 0.919 (0.775–1.090) | 0.333 | 0.830 (0.557–1.238) | 0.362 | ||||
| ≥ 100 g/week | 0.960 (0.833–1.107) | 0.577 | 0.883 (0.636–1.225) | 0.456 | ||||
| Unknown | 0.975 (0.637–1.494) | 0.909 | 1.987 (.0958–4.118) | 0.065 | ||||
| MET, ln (continuous) | 0.992 (.973–1.012) | 0.425 | 0.940 (0.901–0.981) | 0.004 | ||||
| Central obesity | 0.949 (0.839–1.074) | 0.405 | 1.054 (0.794–1.400) | 0.716 | ||||
| Hypertension | 0.977 (0.865–1.104) | 0.713 | 1.053 (0.793–1.400) | 0.720 | ||||
| Diabetes | 1.134 (1.004–1.282) | 0.043 | 1.300 (0.984–1.718) | 0.065 | ||||
| Triglyceridemia | 1.131 (1.003–1.276) | 0.044 | 1.007 (0.761–1.333) | 0.961 | ||||
| Decreased HDL | 1.330 (1.173–1.508) | < 0.001 | 1.183 (1.038–1.348) | 0.012 | 1.074 (0.801–1.441) | 0.632 | ||
Table 4.
Variable associated with I-PSS total, voiding, and storage score.
| IPSS total score | Voiding sub-score | Storage sub-score | ||||
|---|---|---|---|---|---|---|
| B (95% CI) | p | B (95% CI) | p | B (95% CI) | p | |
| Age, years (continuous) | 0.141 (0.121–0.162) | < 0.001 | 0.098 (0.083–0.113) | < 0.001 | 0.048 (0.040–0.057) | < 0.001 |
| Amount of smoking, PY (continuous) | 0.037 (0.025–0.050) | < 0.001 | 0.031 (0.022–0.040) | < 0.001 | 0.007 (0.001–0.012) | 0.013 |
| Marriage (yes vs. others) | 0.287 (0.026–0.548) | 0.031 | ||||
| Low income (yes vs. others) | 0.915 (0.317–1.512) | 0.003 | 0.454 (0.199–0.710) | < 0.001 | ||
| Hypertension (yes vs. others) | − 0.306 (− 0.551 to 0.061) | 0.014 | ||||
Discussion
QoL is becoming a more important health issue and, in elderly men, worsened BPH-induced LUTS exacerbates QoL. Moreover, medical costs for relieving LUTS tend to be significantly increased because of its impact on QoL. However, because of the close relationship between aging and BPH/LUTS, no clear strategies for preventing the development of LUTS have been developed thus far, and prevention strategies for LUTS in men are urgently needed, as mentioned previously. In the current study, we aimed to demonstrate the impact of LUTS on QoL; based on this, we thoroughly assessed the impacts of MetS and lifestyle-related factors on LUTS to suggest the effective prevention strategies for LUTS in men to improve QoL.
Based on the current study, not only severe LUTS but also moderate LUTS affect sleep quality and stress in daily life. Moreover, the presence of LUTS was the most powerful variable associated with both sleep disturbance and stress, followed by younger age and marital status. In other words, preventing the development of moderate to severe LUTS, in addition to alleviating LUTS, could be important medical issues for improving mental health and daily QoL in men. In addition, urologists need to have more interest in mental health and daily QoL, because LUTS is one of the most important factors affecting sleep disorders and stress.
In this study, the amount of life-long smoking was significantly associated with the presence of moderate and severe LUTS, which is consistent with previous studies15. A previous study reported that nicotine might worsen LUTS by reducing bladder flow and urothelial hypoxia15, which supports the results of the current study. Interestingly, the impact of the amount of life-long smoking, not current smoking status16, on voiding symptoms was also observed in the current study, which supports the need for early education on the adverse effects of smoking on LUTS, although these remain to be validated in future studies. Because only a few previous studies have assessed the relationship between smoking and LUTS and these studies generally showed inconsistent results, the findings of the current study could be help clinicians and patients based on a detailed analysis of various factors related to LUTS.
In addition to age, several socioeconomic statuses showed a close relationship with the presence of moderate to severe LUTS in this study, which is similar to previous studies16,17. This might be due to the relationship between psychological stability and LUTS. In a previous studies satisfaction with life and presence of depression was reported to be associated with LUTS progression18,19, which supports these results. In the current study, we revealed that socioeconomic status, including marital status and income level was significantly associated with storage symptom, but not with voiding symptom. These findings thought to come from the association between storage symptom and mental health as previously reported20. In addition because widowhood reported to be associated with a greater likelihood of progression of LUTS21, clinicians should carefully evaluate the LUTS severity and its progression, especially storage symptoms, while they treat patients who lost their spouse.
Based on the current study, alcohol consumption and exercise were not associated with the presence of moderate to severe LUTS in men aged ≥ 40 years. In other words, the prevention of moderate to severe LUTS seemed to be achieved by life-long lifestyle modification and by maintaining a stable socioeconomic status, not by short-term daily life modification. However, because alcohol consumption and exercise were determined as factors associated with decreased sleep disorder, the importance of appropriate alcohol consumption restriction and daily exercise to improve QoL should not be overlooked, especially in mid-aged men. Among MetS and metabolic components, decreased HDL cholesterol was the only variable related to moderate to severe LUTS, which agrees with a previous study9. Interestingly, the presence of hypertension was negatively associated with voiding symptom severity, but not with storage symptoms. These findings might be due to the effects of alleviating LUTS by angiotensin II receptor blocker medication for hypertension as described in previous studies22 although these need to be verified in future studies.
The current study was limited by its cross-sectional study design, although a large number of men who underwent routine health check-ups were included in the analysis. In addition, because of the study design, we could only suggest the relationship between lifestyle and MetS-related variables with the presence of moderate to severe LUTS, and the causality needs to be verified in future studies. However, to our knowledge, this is the first large study to thoroughly assess the relationship not only between LUTS and lifestyle and MetS-related variables, but also its impact on sleep disorders and moderate to severe stress in daily life. Therefore, this study could be useful for clinicians when counselling men, who are not only worried about or experiencing moderate to severe LUTS, but are also having sleep disorders and moderate to severe stress.
In conclusions, in men aged ≥ 40 years, stable socioeconomic status, including married marital status, office worker, and high income, are negatively associated with the presence of moderate to severe LUTS, especially storage symptom. In addition, quitting smoking might be effective lifestyle modification strategies for preventing moderate to severe LUTS and eventually improving quality of life.
Methods
Study population
From 2014 to 2020, men who underwent health check-ups at our institute were eligible for the current study. Among these, 10,353 men who completed the I-PSS questionnaire were initially selected for the study. Then, 3477 duplicated cases were excluded from the analysis. In addition, 1263 men aged < 40 years and 165 men who did not undergo body measurements were excluded. After excluding 54 men who were taking medications for BPH, 40 men with cerebrovascular disease, and 26 men with chronic kidney disease, 5,355 men were finally included in the analysis. The current study was approved by the institutional review board of the Boramae Medical Center and the informed consent has been waived by the institutional review board of the Boramae Medical Center. In addition, all methods were performed in accordance with the relevant guidelines and regulations.
Health check-up
Men who underwent health check-ups at our institute routinely performed the Korean version of I-PSS23, Pittsburgh sleep quality index (PSQI) questionnaires24, and modified Korean-translated brief encounter psychosocial instrument (BEPSI-K)25. Demographic characteristics, including age, body weight, and height, were measured, and social history and lifestyle-related factors, such as smoking, drinking, marital status, job, and income, were collected before medical check-up. We divided the job into three groups (office worker vs. others vs. unknown), marital status into three groups (yes vs. no (including single, divorced, and separated) vs. unknown), and monthly income into three groups (≥ $2684 vs. < $2684 vs. unknown). In addition, smoking status was divided into two groups (current smoker or not), while drinking status was divided into four categories according to weekly alcohol consumption (0 g vs. < 100 g vs. ≥ 100 g vs. unknown). The metabolic equivalent of task (MET) was calculated and log-transformed due to its deviated distribution. Using the NCEP ATP III definition, MetS was defined as the presence of any of the three components among the five metabolic components26. Using PSQI questionnaires, we determined the presence of sleep disorders as ≥ 5 scores27. Using BEPSI-K questionnaires28, the presence of moderate to severe stress was defined as a mean score of ≥ 1.829. Among 5,355 men, 827 patients underwent transrectal ultrasound to measure prostate volume, and the impacts of metabolic components and lifestyle-related variables on prostate volume were analyzed using these men.
Statistical analysis
We divided the participants into three groups according to their I-PSS score (1–7: none to mild vs. 8–19: moderate vs. 20–35: severe). Characteristics are presented as mean ± SD for continuous variables and frequency with proportion for categorical variables. Continuous and categorical variables were compared using the ANOVA test and chi-square test, respectively. We performed univariate and multivariate analyses to reveal the impact of LUTS on sleep disorders and stress. Because both moderate and severe LUTS showed significant impacts on worsening sleep quality and stress status, we determined the variables associated with the presence of moderate to severe LUTS. Patients were subdivided according to age groups, and the proportion of men with moderate to severe LUTS according to lifestyle-related variables, MetS, and metabolic components were calculated and compared. Univariate and multivariate logistic regression analyses were performed to determine the variables associated with the presence of moderate-to-severe LUTS. Variables with p < 0.2 in the univariate analysis were included for multivariable analysis using backward elimination. Because unknown categories in marital status, income, and job showed similar odds ratios compared with others, < $2,684, and others, respectively, marital status, income, and job were re-categorized into two groups for the linear regression analysis. The variables associated with total I-PSS, voiding, and storage sub-scores were determined using univariate and multivariate linear regression analyses. In this study, p < 0.05 was considered statistically significant. All statistical analyses were performed using IBM SPSS Statistics version 26.
Author contributions
J.B.J.: Data collection, Manuscript writing, Data analysis. J.H.L.: Data collection. M.S.C.: Data analysis. D.-W.A.: Data collection. S.H.K.: Data collection. D.S.L.: Data collection. M.C.: Manuscript revision. H.S.: Study design/concept. H.J.: Study design/concept. S.Y.: Study design/concept, Data analysis, Manuscript writing, Manuscript revision.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher's note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Robertson C, et al. The impact of lower urinary tract symptoms and comorbidities on quality of life: the BACH and UREPIK studies. BJU Int. 2007;99:347–354. doi: 10.1111/j.1464-410X.2007.06609.x. [DOI] [PubMed] [Google Scholar]
- 2.Coyne KS, et al. The burden of lower urinary tract symptoms: evaluating the effect of LUTS on health-related quality of life, anxiety and depression: EpiLUTS. BJU Int. 2009;103:4–11. doi: 10.1111/j.1464-410X.2009.08371.x. [DOI] [PubMed] [Google Scholar]
- 3.Irwin DE, Kopp ZS, Agatep B, Milsom I, Abrams P. Worldwide prevalence estimates of lower urinary tract symptoms, overactive bladder, urinary incontinence and bladder outlet obstruction. BJU Int. 2011;108:1132–1138. doi: 10.1111/j.1464-410X.2010.09993.x. [DOI] [PubMed] [Google Scholar]
- 4.Van Exel N, et al. Medical consumption and costs during a one-year follow-up of patients with LUTS suggestive of BPH in six European countries: report of the TRIUMPH study. Eur Urol. 2006;49:92–102. doi: 10.1016/j.eururo.2005.09.016. [DOI] [PubMed] [Google Scholar]
- 5.Ford ES. Risks for all-cause mortality, cardiovascular disease, and diabetes associated with the metabolic syndrome: A summary of the evidence. Diabetes Care. 2005;28:1769–1778. doi: 10.2337/diacare.28.7.1769. [DOI] [PubMed] [Google Scholar]
- 6.Vanhanen M, et al. Association of metabolic syndrome with Alzheimer disease: A population-based study. Neurology. 2006;67:843–847. doi: 10.1212/01.wnl.0000234037.91185.99. [DOI] [PubMed] [Google Scholar]
- 7.Cowey S, Hardy RW. The metabolic syndrome: a high-risk state for cancer? Am. J. Pathol. 2006;169:1505–1522. doi: 10.2353/ajpath.2006.051090. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Li, J. et al. The association between metabolic syndrome and benign prostatic hyperplasia: a systematic review and meta-analysis. Aging Male. 1–12 (2020). [DOI] [PubMed]
- 9.Yoo S, et al. The impacts of metabolic syndrome and lifestyle on the prevalence of benign prostatic hyperplasia requiring treatment: historical cohort study of 130 454 men. BJU Int. 2019;123:140–148. doi: 10.1111/bju.14528. [DOI] [PubMed] [Google Scholar]
- 10.Yoo S, et al. Effects of metabolic syndrome on the prevalence of prostate cancer: Historical cohort study using the national health insurance service database.J. Cancer Res. Clin. Oncol. 2019;145:775–780. doi: 10.1007/s00432-019-02842-1. [DOI] [PubMed] [Google Scholar]
- 11.Pashootan P, Ploussard G, Cocaul A, de Gouvello A, Desgrandchamps F. Association between metabolic syndrome and severity of lower urinary tract symptoms (LUTS): An observational study in a 4666 European men cohort. BJU Int. 2015;116:124–130. doi: 10.1111/bju.12931. [DOI] [PubMed] [Google Scholar]
- 12.Kupelian V, et al. Association of lower urinary tract symptoms and the metabolic syndrome: results from the Boston Area Community Health Survey. J. Urol. 2009;182:616–625. doi: 10.1016/j.juro.2009.04.025. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Park HK, et al. Relationship between lower urinary tract symptoms and metabolic syndrome in a community-based elderly population. Urology. 2008;72:556–560. doi: 10.1016/j.urology.2008.03.043. [DOI] [PubMed] [Google Scholar]
- 14.Gao Y, et al. Are metabolic syndrome and its components associated with lower urinary tract symptoms? Results from a Chinese male population survey. Urology. 2012;79:194–201. doi: 10.1016/j.urology.2011.07.1399. [DOI] [PubMed] [Google Scholar]
- 15.Nagai T, et al. Nicotine-induced hypoxia in rat urothelium deteriorates bladder storage functions. Neurourol. Urodyn. 2019;38:1560–1570. doi: 10.1002/nau.24050. [DOI] [PubMed] [Google Scholar]
- 16.Bradley CS, et al. Evidence of the impact of diet, fluid intake, caffeine, alcohol and tobacco on lower urinary tract symptoms: A systematic review. J. Urol. 2017;198:1010–1020. doi: 10.1016/j.juro.2017.04.097. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Fowke JH, Munro H, Signorello LB, Blot WJ, Penson DF, Urologic Diseases of America Project Association between socioeconomic status (SES) and lower urinary tract symptom (LUTS) severity among black and white men. J. Gen. Intern. Med. 2011;26:1305–1310. doi: 10.1007/s11606-011-1776-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Rohrmann S, Katzke VA, Kaaks RJU. Lifestyle and Progression of Lower Urinary Tract Symptoms in German Men—Results From the EPIC-Heidelberg Cohort. Urology. 2018;120:192–196. doi: 10.1016/j.urology.2018.06.013. [DOI] [PubMed] [Google Scholar]
- 19.Jeong S-M, et al. Depression and its severity are strongly associated with both storage and voiding lower urinary tract symptoms independently of prostate volume.J. Korean Med. Sci. 2015;30:1646–1651. doi: 10.3346/jkms.2015.30.11.1646. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Martin S, et al. Lower urinary tract symptoms, depression, anxiety and systemic inflammatory factors in men: a population-based cohort study. PLoS One. 2015;10:e0137903. doi: 10.1371/journal.pone.0137903. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Martin S, et al. Risk factors for progression or improvement of lower urinary tract symptoms in a prospective cohort of men. J. Urol. 2014;191:130–137. doi: 10.1016/j.juro.2013.06.018. [DOI] [PubMed] [Google Scholar]
- 22.Ito H, et al. IPSS is lower in hypertensive patients treated with angiotensin-II receptor blocker: posthoc analyses of a lower urinary tract symptoms population. Neurourol. Urodyn. 2013;32:70–74. doi: 10.1002/nau.22267. [DOI] [PubMed] [Google Scholar]
- 23.Choi HR, et al. Translation validity and reliability of I-PSS Korean version.Korean. J. Urol. 1996;37:659–665. [Google Scholar]
- 24.Sohn SI, Kim DH, Lee MY, Cho YW. The reliability and validity of the Korean version of the Pittsburgh Sleep Quality Index. Sleep Breath. 2012;16:803–812. doi: 10.1007/s11325-011-0579-9. [DOI] [PubMed] [Google Scholar]
- 25.Kim KN, et al. Degree of stress and stress-related factors by the Korean version of the BEPSI. J. Korean. Acad. Fam. Med. 1998;19:559–570. [Google Scholar]
- 26.Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults et al. Executive summary of the third report of the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III) JAMA. 2001;285:2486–2497. doi: 10.1001/jama.285.19.2486. [DOI] [PubMed] [Google Scholar]
- 27.Buysse DJ, Hall ML, Strollo PJ, Kamarck TW, Owens J, Lee L, Reis SE, Matthews KA. Relationships between the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Clinical/Polysomnographic Measures in a Community Sample. J. Clin. Sleep. Med. 2008;4(6):563–571. doi: 10.5664/jcsm.27351. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Frank SH, Zyzanski SJ. Stress in the clinical setting: the brief encounter psychosocial instrument. J. Fam. Pract. 1998;26:533–539. [PubMed] [Google Scholar]
- 29.Lee SP, et al. The effect of emotional stress and depression on the prevalence of digestive diseases. J. Neurogastroenterol. Motil. 2015;21:273. doi: 10.5056/jnm14116. [DOI] [PMC free article] [PubMed] [Google Scholar]