Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a chronic pain disorder, which is characterized by the presence of noninfectious pelvic or perineal pain lasting longer than 3 months. The International Prostatitis Collaborative Network of the National Institutes of Health (IPCN-NIH) has provided detailed criteria for diagnosing CP/CPPS [
Although there have been many basic and clinical research studies, the exact etiology, pathophysiology, and mechanism of CP/CPPS remain indeterminate. This syndrome is currently considered to be a multifactorial medical condition and requires a multimodal treatment approach [
Currently, CP syndromes represent an important healthcare problem worldwide [
A cross-sectional study about CP/CPPS patients has been done previously; it was reported that there were many potential factors that might have an influence on CP/CPPS, including smoking, drinking tea, sedentariness, overstress, economic pressure, and self-health cognition [
This case-control study was conducted in Yiling District, Yichang, Hubei Province, China. The study included one administrative district, one economic development zone, eight towns, and three townships. With a total area of 3424 square kilometers and a population of 546,500, this district is the most populous administrative region of Yichang. Most of the residents are drivers or laborers. The target populations of this study are composed of male patients diagnosed with CP/CPPS for the first time in Yiling Hospital and healthy men without CP/CPPS symptoms in Yiling District. Data were collected from 279 patients with CP/CPPS between September 2012 and May 2013. Five hundred and fifty-eight males matched by age (1 : 2) without CP/CPPS symptoms were enrolled into the control group.
Diagnosis of patients with CP/CPPS was based on the IPCN-NIH consensus [
The study was approved by the Medical Ethics Committee of Wuhan University of Science and Technology. Written informed consent was obtained from the study subjects who were assured of confidentiality by the use of anonymous questionnaires. Verbal consent was also sought from community leaders prior to the focus group discussions.
An anonymous questionnaire was designed by experts on health statistics and urology, and all of the collectors were trained before the questionnaire survey. According to the results of a presurvey, the questionnaire and plan were modified. The questionnaire was proved to be valid. Finally, the questionnaire consisted of five major domains of items, including demographics (age, degree of education, occupation, medical insurance, and average monthly income), lifestyle (frequency of eating fast food, time of using a mobile per day, smoking, drinking, drinking tea, and sedentariness), working situation (occupational hazards, night shift), psychological status (severity of bad mood, stress of work, economic stress of family, self-health cognition, and spousal relationship), and a physical exam. The item of occupational hazards determined by type of work was asked by questionnaire investigators. The questionnaire was self-administered after informed consent unless the participant was illiterate.
The collected questionnaires were collated manually for the first time. They were then checked again while the data were entered into the database set up by Epi database. Data were analyzed using descriptive statistical methods, the chi-square test, and conditional logistic regression analysis. The Statistical Package for Sciences (SPSS) software version 17.0 (SPSS Inc., Chicago, IL, USA) was used for data analysis. The significance level was set at
A total of 279 patients and 558 controls were recruited to participate in this retrospective survey. All of the participants completed the questionnaire. The age of all of the subjects ranged from 24 to 59 years. The mean age of all of the subjects was
For cases, 72.04% of subjects were aged between 30 and 49 years. Only one subject was illiterate, and most (82.79%) had a middle school or high school diploma. A total of 78.14% of the patients were employed as skilled laborers. A total of 86.73% of the patients had medical insurance for urban workers except for 3 who were reported as self-paying when seeing a doctor. More than 80% of the patients had an average monthly income less than 3000 CNY (483 USD), and only 10 patients had an average monthly salary of more than 5000 CNY (805 USD) (Table
Sociodemographic characteristics of respondents (
Characteristic | Value | Cases |
Controls |
---|---|---|---|
Age | 24~ | 15 (5.38%) | 42 (7.53%) |
30~ | 70 (25.09%) | 136 (24.37%) | |
40~ | 131 (46.95%) | 267 (47.85%) | |
50~ | 63 (22.58%) | 113 (20.25%) | |
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Degree of education | No formal education | 1 (0.36%) | 0 (0.00%) |
Primary school | 2 (0.72%) | 19 (3.40%) | |
Junior high school | 105 (37.63%) | 179 (32.08%) | |
Senior high or technical secondary school | 126 (45.16%) | 258 (46.24%) | |
Junior college or above | 45 (16.13%) | 102 (18.28%) | |
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Occupation | Unskilled; for example, trader, farming | 20 (7.17%) | 34 (6.09%) |
Skilled labor; for example, driver, blue-collar worker | 218 (78.14%) | 450 (80.65%) | |
Professional; for example, teacher, healthcare worker, office worker | 6 (2.15%) | 20 (3.58%) | |
Others | 35 (12.54%) | 54 (9.68%) | |
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Medical insurance | Medical insurance for urban workers | 242 (86.73%) | 484 (86.73%) |
Rural cooperative medical service | 30 (10.75%) | 57 (10.21%) | |
Commercial insurance | 3 (1.08%) | 6 (1.08%) | |
Self-paying | 3 (1.08%) | 5 (0.90%) | |
Others | 1 (0.36%) | 6 (1.08%) | |
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Average monthly income | Less than 1000 CNY | 40 (14.34%) | 71 (12.72%) |
1000–2000 CNY | 106 (37.99%) | 206 (36.92%) | |
2000–3000 CNY | 78 (27.96%) | 161 (28.85%) | |
3000–4000 CNY | 31 (11.11%) | 62 (11.11%) | |
4000–5000 CNY | 14 (5.02%) | 30 (5.38%) | |
More than 5000 CNY | 10 (3.58%) | 28 (5.02%) |
Similarly, 72.22% of the controls were aged between 30 and 49 years. Most of the controls were employed as skilled laborers. A total of 86.73% of the controls had medical insurance for urban workers, whereas five subjects were reported as self-paying when seeing a doctor. Almost 80% of the control subjects’ average monthly income was less than 3000 CNY (483 USD). All of the controls received school education, and 82.79% had a secondary school or high school diploma (Table
Table
Values of significant risk factors.
Variable | Value | ||
---|---|---|---|
CP/CPPS | No = 0 | Yes = 1 | |
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Occupational hazards | No factors = 0 | Physical factors = 1 | Chemical factors = 2 |
Biological factors = 3 | Other factors = 4 | ||
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Night shift | Yes = 1 | No = 2 | |
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Frequency of eating fast food | Frequent = 1 | Once in a while = 2 | Never = 3 |
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Time of using a mobile per day | Less than half an hour = 1 | Half an hour to one hour = 2 | |
One hour to two hours = 3 | Two hours to three hours = 4 | ||
Three hours to four hours = 5 | More than four hours = 6 | ||
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Severity of mood (e.g., sadness, anxiety, depression) | Not a bit = 1 | A bit = 2 | Medium = 3 |
Very serious = 4 | Extremely serious = 5 | ||
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Stress of work | Not a bit = 1 | A bit = 2 | Medium = 3 |
Very serious = 4 | Extremely serious = 5 | ||
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Economic stress of family | Not a bit = 1 | A bit = 2 | Medium = 3 |
Very serious = 4 | Extremely serious = 5 | ||
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Self-health cognition | Beyond comparison = 1 | Very good = 2 | Good = 3 |
Common = 4 | Bad = 5 | ||
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Spousal relationship | Very good = 1 | Common = 2 | Bad = 3 |
CP/CPPS: chronic prostatitis/chronic pelvic pain syndrome.
Results of the chi-square test for single-factor analysis.
Factors |
|
SE | Wald | df | Sig. | Exp ( |
95.0% CI for Exp ( |
|
---|---|---|---|---|---|---|---|---|
No occupational hazards | — | — | 15.372 | 4 | 0.004 | — | — | — |
Chemical factors | 0.713 | 0.187 | 14.620 |
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1.416 | 2.941 | |
Not on night shift |
|
0.144 | 8.769 | 1 |
|
|
0.493 | 0.866 |
Low frequency of eating fast food |
|
0.130 | 4.540 | 1 |
|
|
0.587 | 0.978 |
Time of using a mobile per day | 0.142 | 0.059 | 5.793 | 1 |
|
|
1.027 | 1.293 |
Severity of mood (e.g., sadness, anxiety, depression) | 0.525 | 0.115 | 20.848 | 1 |
|
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1.350 | 2.119 |
Stress of work | 0.280 | 0.083 | 11.317 | 1 |
|
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1.124 | 1.557 |
Economic stress of family | 0.155 | 0.076 | 4.147 | 1 |
|
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1.006 | 1.354 |
Self-health cognition | 0.325 | 0.086 | 14.355 | 1 |
|
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1.170 | 1.637 |
Spousal relationship | 0.414 | 0.141 | 8.593 | 1 |
|
|
1.147 | 1.996 |
Nine significant factors selected by the chi-square test were used to build the regression model. Occupational hazards were set as classification variables, using the forward Wald method. Probability values for stepwise entry and removal were 0.05 and 0.10, respectively. Finally, four factors were included in the regression model (Table
Results of conditional logistic regression for multiple-factor analysis.
Factors |
|
SE | Wald | df | Sig. | Exp ( |
95.0% CI for Exp ( |
|
---|---|---|---|---|---|---|---|---|
No occupational hazards | — | — | 11.919 | 4 | 0.018 | — | — | — |
Physical factors | 0.269 | 0.255 | 1.117 | 1 | 0.291 | 1.309 | 0.794 | 2.158 |
Chemical factors | 0.657 | 0.193 | 11.546 | 1 |
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1.321 | 2.819 |
Biological factors | 0.417 | 0.651 | 0.411 | 1 | 0.522 | 1.518 | 0.424 | 5.438 |
Others | 0.360 | 0.250 | 2.074 | 1 | 0.150 | 1.433 | 0.878 | 2.339 |
Not on night shift |
|
0.149 | 6.365 | 1 |
|
|
0.513 | 0.920 |
Severity of mood (e.g., sadness, anxiety, depression) | 0.482 | 0.120 | 16.213 | 1 |
|
|
1.280 | 2.046 |
Self-health cognition | 0.265 | 0.090 | 8.741 | 1 |
|
|
1.094 | 1.555 |
Prostatitis has become increasingly more common, and age is not a limiting factor. Given the complexity of prostatitis, a systematic classification was provided by the NIH, including category I (acute bacterial prostatitis), category II (chronic bacterial prostatitis), category III (chronic bacterial prostatitis/CPPS), and category IV (asymptomatic inflammatory prostatitis) [
In addition, the quality of life obviously declines in patients with CP/CPPS. Wenninger et al. [
Thus, many epidemiologic studies have been done to find key risk factors of the disease and help people change their lifestyle to reduce the risk of CP/CPPS. Lan et al. [
Dietary habit is often considered to have a considerable effect on CP/CPPS. According to our chi-square test results, among the lifestyle factors in the questionnaire, only “frequency of eating fast food” was significant. Finally, this factor was not included in the regression model. Many foods, such as spicy food, coffee, alcoholic beverages, and tea, can exacerbate the symptoms of patients with CP/CPPS, while others, such as docusate, psyllium, water, herbal teas, and polycarbophil, can ameliorate symptoms [
There were some limitations in our study. First, because this study was a retrospective study, it could not provide sufficient evidence of a causal relationship between risk factors and CP/CPPS. Second, the questionnaire was self-designed, despite its reliability, and bias might have been present. Third, chemical occupational factors have not been divided into particular toxicity or hazard, which may be confusing.
Many studies have shown a relationship between CP/CPPS and potential risk factors. An increasing number of researchers support the viewpoint that CP/CPPS is a clinical syndrome with an unclear or unknown pathogenesis. Our study shows that chemical factors, night shifts, the moods of sadness, anxiety, depression, and poor self-health cognition may affect CP/CPPS. Although there are many limitations in this study, our results might provide instructive information for patients and urologists.
Yan Wang and Chen Chen are coauthors.
None of the authors declare competing financial interests.
Yan Wang, Changcai Zhu, Liang Chen, and Chen Chen designed the questionnaire and performed the survey and data analysis; Qingrong Han and Huarong Ye carried out the physical examinations; Yan Wang and Changcai Zhu wrote the paper. All authors have read and approved the final version of the paper and agree with the order of presentation of the authors. Yan Wang and Chen Chen equally contributed to this paper.
The authors would like to thank all of the workers who took part in this research, especially the doctors at Yiling Hospital, Yichang, Hubei Province. This study was funded by three research projects, called the Male Reproductive Health Status and Intervention Countermeasures in Three Gorges Region of Yichang (WJ2015Z087), a Case-Control Study on Influential Factors of Chronic Prostatitis among Iron and Steel Enterprise Male Workers (WJ2015MB256), which were provided by the Health and Family Planning Commission of Hubei Province, and a grant from the Undergraduates Innovation Fund of Hubei Province (201310488041), which was provided by Hubei Provincial Department of Education.