**2. Epidemiology – Benign prostatic hyperplasia and chronic kidney disease**

Benign prostatic hyperplasia is characterized by the nonmalignant overgrowth of prostatic tissue surrounding the urethra, ultimately constricting the urethral opening and giving rise to associated lower urinary tract symptoms (McVary 2006; Wei, Calhoun et al. 2008).

Diagnosis of BPH is made based on histologic examination of a prostatic tissue (biopsy, surgery or autopsy), however surrogate measures, namely lower urinary symptoms, bladder outlet obstruction and prostate enlargement are often used to define BPH as a clinical syndrome (Emberton, Andriole et al. 2003). For this reason, many consequences of BPH are not studied for it is impractical. This factgives us limited insight into the incidence and progression of the disease (Jacobsen, Girman et al. 2001). The prevalence of BPH thus can be calculated on the basis of histologic criteria (autopsy prevalence) or clinical criteria (clinical prevalence) (Wein 2007).

The 1984 milestone study by Berry and colleagues summarized the data from five studies demonstrating that no men younger than 30 had evidence of BPH and the prevalence rose with each age group, peaking at 88% in men in their 80s (Berry, Coffey et al. 1984).

BPH is considered a disease of aging male and can have a familial inheritance, especially if large prostate volumes and surgical intervention at a young age are seen in the pedigree (Wein 2007).

Definitions of BPH, have undergone several changes in the past decade, and, at present, no single criterion can be applied. In the past, the term "prostatism" was used, incorrectly referring to the prostate as the sole source of the typical LUTS (lower urinary tract symptoms) found in aging men. It has been pointed out that there are at least three interrelated phenomena that can be assessed independently, namely the symptoms (Wein 2007), enlargement of the prostate gland and presence of obstruction (Nielsen, Nordling et al. 1994). In a given patient, all three, two of the three, or only one of the three entities might be present. Paul Abrams was the investigator that changed the earlier and inappropriate term (prostatism) to lower urinary tract symptoms (LUTS) (Nielsen, Nordling et al. 1994; Abrams 1999)

BPH (histologically) is present in about 8% of men aged 31 to 40 years, and this prevalence increases markedly with age to about 90% by ninth decade(Berry, Coffey et al. 1984; Rosen, Altwein et al. 2003; McVary 2006). Studies in United States, England, Austria, Norway, Denmark, China, Japan, and India showed that the prevalence of BPH increases rapidly in the fourth decade of life, reaching nearly 100% in the ninth decade (Harbitz and Haugen 1972; Carter and Coffey 1990; Wein 2007) (Pradhan and Chandra 1975). It is striking that the age-specific autopsy prevalence is remarkably similar in all populations studied regardless of ethnic and geographic origin (Berry, Coffey et al. 1984).

However, we must take into account the aging population and increasing number of patients who need medical care for symptoms (LUTS) or consequences of BPH. Number of

The purpose of this chapter is to discuss the relationship between BPH and CKD, bearing in mind the epidemiology, pathophysiology, the clinical and imagiologic presentation of BPH

**2. Epidemiology – Benign prostatic hyperplasia and chronic kidney disease**  Benign prostatic hyperplasia is characterized by the nonmalignant overgrowth of prostatic tissue surrounding the urethra, ultimately constricting the urethral opening and giving rise

Diagnosis of BPH is made based on histologic examination of a prostatic tissue (biopsy, surgery or autopsy), however surrogate measures, namely lower urinary symptoms, bladder outlet obstruction and prostate enlargement are often used to define BPH as a clinical syndrome (Emberton, Andriole et al. 2003). For this reason, many consequences of BPH are not studied for it is impractical. This factgives us limited insight into the incidence and progression of the disease (Jacobsen, Girman et al. 2001). The prevalence of BPH thus can be calculated on the basis of histologic criteria (autopsy prevalence) or clinical criteria

The 1984 milestone study by Berry and colleagues summarized the data from five studies demonstrating that no men younger than 30 had evidence of BPH and the prevalence rose

BPH is considered a disease of aging male and can have a familial inheritance, especially if large prostate volumes and surgical intervention at a young age are seen in the pedigree

Definitions of BPH, have undergone several changes in the past decade, and, at present, no single criterion can be applied. In the past, the term "prostatism" was used, incorrectly referring to the prostate as the sole source of the typical LUTS (lower urinary tract symptoms) found in aging men. It has been pointed out that there are at least three interrelated phenomena that can be assessed independently, namely the symptoms (Wein 2007), enlargement of the prostate gland and presence of obstruction (Nielsen, Nordling et al. 1994). In a given patient, all three, two of the three, or only one of the three entities might be present. Paul Abrams was the investigator that changed the earlier and inappropriate term (prostatism) to lower urinary tract symptoms (LUTS) (Nielsen, Nordling et al. 1994;

BPH (histologically) is present in about 8% of men aged 31 to 40 years, and this prevalence increases markedly with age to about 90% by ninth decade(Berry, Coffey et al. 1984; Rosen, Altwein et al. 2003; McVary 2006). Studies in United States, England, Austria, Norway, Denmark, China, Japan, and India showed that the prevalence of BPH increases rapidly in the fourth decade of life, reaching nearly 100% in the ninth decade (Harbitz and Haugen 1972; Carter and Coffey 1990; Wein 2007) (Pradhan and Chandra 1975). It is striking that the age-specific autopsy prevalence is remarkably similar in all populations studied regardless

However, we must take into account the aging population and increasing number of patients who need medical care for symptoms (LUTS) or consequences of BPH. Number of

of ethnic and geographic origin (Berry, Coffey et al. 1984).

with each age group, peaking at 88% in men in their 80s (Berry, Coffey et al. 1984).

to associated lower urinary tract symptoms (McVary 2006; Wei, Calhoun et al. 2008).

and how it can contribute to CKD.

(clinical prevalence) (Wein 2007).

(Wein 2007).

Abrams 1999)

consultations for BPH and urinary symptoms constitute the largest share of visits in our department and in urology departments worldwide. In 1989, there were approximately 1,3 million office visits to physician for BPH (Schappert 1993), and in 1992 approximately 170.000 prostatectomies were performed among inpatients in the United States (Xia, Roberts et al. 1999; Wei, Calhoun et al. 2008). Agency for Health Care Policy and Research Diagnostic and Treatment for BPH showed that from 22.5 million white men aged 50 to 79 years in the United States, in 1990, approximately 5.6 million needed medical consultation and treatment for BPH, demonstrating this disease is a prevalent health problem (Wei, Calhoun et al. 2008).

Although BPH is not a life-threatening condition, the impact of BPH on quality of life (QoL) can be significant and should not be underestimated (McVary 2006). According to the World Health Organization although the death rate attributable to BPH is negligible, the estimated DALY's (The sum of years of potential life lost due to premature mortality and the years of productive life lost due to disability) due to BHP is quite considerable. Most of the disability is probably due to severe clinical symptoms and/or late complications of BPH like CKD (Organization 2011).

Chronic kidney disease is a serious condition associated with premature mortality, decreased quality of life, and increased health-care expenditures. Untreated CKD can result in end-stage renal disease requiring dialysis or kidney transplantation.

The 1999-2004 National Health and Nutrition Examination Survey (NHANES) determined that 16.8% of the U.S. population aged >20 years had CKD (according to 1999-2004 data), compared with 14.5% from the 1988-1994 NHANES, an increase of 15.9% based on crude estimates of prevalence (Saydah 2007) which reflects the increasing needs for health care policy for CKD.
