The present hospital-based, cross-sectional study was conducted in the Department of Biochemistry, Government Medical College, Patiala, Punjab, India. About 162 BPH patients consulted to the Urology Department of Rajindra Hospital, Patiala from December 2014 to November 2015 and were required to undergo serum PSA evaluation. Informed written consent was obtained from all the enrolled patients after explaining them the details of the study in their own language. The present study was approved by the institutional ethical committee (Bio/14/546).

Patients’ selection was based on exclusion-inclusion criteria.

Inclusion criteria: Patients of more than 50 years of age who were presenting with Lower Urinary Tract Symptoms (LUTS).

Exclusion criteria: Patients below the age of 50 years and patients with carcinoma of the prostate. Patients on any drugs that effect on the level of serum PSA i.e., (5-α-reductase inhibitors) or the history of diabetes, tuberculosis, urinary tract infection and hypertension were also excluded from the study.

Taking all aseptic and antiseptic precautions, 5 mL of blood (EDTA and plain vial) sample was drawn from the median cubital vein. Overnight fasting samples were used for all the investigations. Blood was allowed to clot and samples were centrifuged at 2200-2500 rpm (revolution per minute) for 15 minutes at room temperature. The vials containing separated serum sample were labeled properly and stored at -20°C, if estimations were not done within eight hours of collection of the blood. All the estimations were carried out within 24 hours of collection of blood samples.

Methods of evaluation: Complete Blood Count (CBC) was done by auto analyser (Transasia Bio-medicals Ltd.,) [8]. Total Serum Protein (TSP) was estimated by the Biuret method, FBG by glucose oxidase method, serum urea by modified Berthelot method, serum creatinine by Brod and Sirota method by using semi-auto analyser [9-12]. Glucose and creatinine were measured at 505 nm. Total protein was at 546 nm and urea was measured at 578 nm. ERBA diagnostics Manheim marketed Transasia Bio-Medicals Ltd., (HP) glucose (979852), urea (120214), creatinine (120246), and total protein (120206) kits were used. The serum PSA levels of these patients were estimated through Sandwich ELISA (enzyme linked immunosorbent assay) by ELISA PSA kit (Cal Biotech Company, PS235T) [13]. Ultrasonography was done for all the patients. Prostate volume was calculated by ellipsoid formula (π/6×height×length×width). Height, length and width of the prostate were measured by transabdominal ultrasonography. Transrectal examination was done to rule out any suspicious lesion in patients with serum PSA >4 ng/mL. PSA density was calculated by PSA/PV.

Data was expressed as Mean±SD. The data was analysed statistically. ANOVA test was used to determine the assocation of PSA with age. Correlations were evaluated using Pearson correlation coefficient. Statistical analysis was done by using GraphPad InStat version 3.00. All the statistical graphs were plotted using Microsoft Excel 2009. p-value <0.001 was considered statistically significant.

Routine investigations (CBC, TSP, FBG, serum urea and serum creatinine) were within normal limit in this study and therefore no statistical test was done for these parameters. The maximum number of patients was in 60-69 years age group with PSA ranging from 0.48-12.06 ng/mL and mean PSA was 3.32±2.67 ng/mL. The changes in PSA levels among different age groups were analysed. No significant difference between the groups on account of PSA parameter (p=0.445) (r= -0.05) was observed [Table/Fig-1].

In BPH patients the mean PSA was 17.85±13.80 ng/mL and the mean PV was 37.20±32.78 mL. The p-value was <0.001 (r=0.59) which was statistically highly significant.

In BPH patients the mean PSA was 17.85±13.80 ng/mL and the mean PSA density was 0.12±0.04 ng/mlcc. The p-value was <0.001 (r=0.56) which was statistically significant.

Present study found that age was not associated with PSA. PSA did not increase or decrease with respect to age strata in BPH patients. In our study highest range of PSA (0.48-12.06 ng/mL) was in 60-69 years age group and lowest range of PSA (2.07-5.6 ng/mL) was in 90-93 years age group. The maximum numbers of patients were in the age group 60-69 years which was similar to the study of Deori R et al., [7]. In contrast to our study, Mosli HA et al., Casey RG et al., and Deori Ret al., demonstrated that age was significantly (p-value <0.001) correlated with PSA and PSA levels increased with age [5-7]. According to Casey RG et al., age specific reference ranges were introduced to increase the specificity and sensitivity of a PSA. According to their study, increased PSA reflect the increase prevalence of pathology rather than a physiological process of ageing [6]. Deori R et al., demonstrated that BPH is age related and the prevalence increases with increasing age [7]. The risk of prostate cancer is high when the total PSA is more than 10 ng/mL and conversely low in patients with a total PSA is less than 4 ng/mL. The range of 4 to 10 ng/mL represents the ‘grey zone’ [14]. The age specific range of serum PSA levels makes it more efficient tumour marker for detection of clinical cancer in elderly men. In BPH patients, the size of prostate increases which ultimately leads to elevated serum PSA levels. Due to lack of well-documented sensitivity and specificity data, several investigations were undertaken to study the ability of PSA to differentiate between benign processes [Table/Fig-2] [5-7].

PV levels fluctuate significantly throughout man’s lifetime, and in the course of different prostatic diseases including BPH. The mean PSA in the present study was 17.85±13.80 ng/mL and the mean PV was 37.20±32.07 mL [Table/Fig-3] [5,7,15,16]. PSA and PV were significantly (p-value <0.001) associated which was almost similar to other studies. Mosli HA et al., demonstrated PV and PSA are key predictors of clinical progression, response to medical treatment and prostate-related events in patients. Levels of PV and PSA were highly variable among different ages. Age was found to be significant but had weak positive correlations with PV and PSA. Only PSA and PV showed a significant and strong positive correlation (r=0.44) [5]. Park DS et al., also reported that PSA levels not only had a strong correlation with PV, but they were also a strong predictor of PV in a large scale Korean screening cohort [15]. PSA is an organ-specific biomarker of the prostate that increases on disruption of the normal anatomic prostatic tissue due to malignant or benign prostatic diseases. In Indonesian men with BPH, both PV and PSA increased with age and PV was found to be significantly correlated with PSA [16]. In a study by Deori R et al., changes in PV and serum PSA vary among different ages. PSA and PV demonstrated a significant and strong positive correlation (r=0.93) [7]. The mean PSA in our study was more than the two studies (Putra IB et al., and Deori R et al.,) may be due to sample size of the study population.

In the present study, PSA and PSA density was significantly correlated (p-value <0.001) in BPH patients which was similar to other studies [Table/Fig-4] [17-19]. PSA density is an accurate predictor for adverse pathology prediction. The accuracy and potential improvement in sensitivity and specificity associated with the use of PSA density are limited by several factors. PSA density is able to better reflect biologic differences between prostate cancer and BPH, enhancing diagnostic discriminative power for the population with PSA levels in the ‘grey zone’ [17]. PSA density is a derivative measure that involves dividing the serum PSA specificity by adjusting for that component of the serum PSA that may arise from benign elements. The largest determinant of prostate size is the transition zone, with expansion resulting from the development of benign prostatic hypertrophy [18]. Kuppusamy S et al., found that PSA density value improves the diagnostic performance of total PSA level, especially in the range of 4.01 to 30.00 ng/mL as the incidence and cancer detection was quite low. An increased cut-off value PSA density (>0.19) and Digital Rectal Examination (DRE) eliminates the need of multiple biopsies and helps in diagnosis of cancer [19].

In our study, no correlation was observed between serum PSA and advancing age in BPH patients, but prostate size was found to be significantly correlated with serum PSA. Therefore, before interpreting PSA values, prostate size and PSA density should be taken into consideration.

Further studies with larger sample size and age-matched control group are required to validate our findings and to improve the diagnostic performance of PSA while examining the relationship between prostate volume, PSA density and patient age.

The age of BPH patients was not correlated with PSA levels. PSA did not increase or decrease among different age groups in this study. Therefore the age of the patients should not be taken into consideration while interpreting PSA levels. PSA density increases the diagnostic value of PSA. PSA and prostate volume were significantly correlated in BPH patients. Increase in prostate volume is associated with increased serum PSA level. PSA levels depicts approximate prostate volume, and may have clinical potential in the management of patients with BPH.