Obesity–PSA relationship: a new formula

Abstract

To clinically apply the inverse PSA-body mass index (BMI) correlation and enhance PSA sensitivity in obese cases, a new formula is warranted. An innovated BMI-PSA equation is designed. PSA-BMI adjusted formula (named Hekal's equation): measured total PSA (ng ml À1 ) multiplied by age (years) and divided by BMI of the patient. The formula is applied over a randomly chosen 1000 cases of different PSA, BMI, age and trans-rectal ultrasound biopsy results, the yield of new PSA is correlated with pathology and age-specific PSA adjustment values. Among the 988 cases with complete data, obesity (BMI: 30-35 kg m À2 ) in 236 cases (23.8%) and 79 cases (7.9%) have BMI435 kg m À2 . Mean PSA was 5.8 ng ml À1 (s.d.±8.4 ng ml À1 ). Cases stratified based on their age (every 10 years). The new equation was applied. Obesity is detected in 33.5 and 43.6% of fifth and sixth decade of life respectively (P ¼ 0.02), with low measured PSA values (2.1, 3.8 ng ml À1 , respectively). By such PSA measurement biopsy may be omitted, missing 53.3% of malignant cases. In contrast, PSA adjusted were 4 and 9.3 ng ml À1 within the same group of patients. With such values, the decision of a biopsy could not be missed for the targeted groups. Specificity and sensitivity of adjusted PSA values at cutoff point 4 ng ml À1 was 41.7 and 70%, respectively. Based on our results, the new PSA-BMI adjusted formula is reproducible, easy applied formula. With such a formula the higher sensitivity of PSA in obese patients could be achieved. The misleading low PSA in obese cases in the fifth and sixth decade will be corrected.

Diabetes and prostate cancer risk in the REDUCE trial

“…3 Furthermore, as obesity also lowers serum PSA due to hemodilution, its frequent co-existence with diabetes may further impair PCa detection in diabetics. [15][16][17] To address this, we investigated the relationship between diabetes and PCa risk in the REDUCE trial. ).…”

“…13,14 Moreover, obesity, which often accompanies diabetes, also depresses PSA through hemodilution, and this may contribute to even lower PSA values in diabetics. [15][16][17] Specifically, as most PCa cases are detected on biopsy following an abnormal PSA screen, lower PSA in men with diabetes and possible co-morbid obesity may obscure true prostatic disease by triggering fewer biopsies and leading to artificially lower rates of PCa diagnosis.…”

A Obesidade e seus Efeitos no Diagnóstico do Câncer de Próstata e Níveis Séricos do Antígeno Prostático Específico (PSA)

“…Além disso, os homens com IMC mais alto também têm maiores volumes de plasma, o que poderia diminuir as concentrações séricas do PSA -fenômeno conhecido como hemodiluição (Hekal & Ibrahiem, 2010]. Online).…”

Prostate Cancer in Elderly Croatian Men: 5-HT Genetic Polymorphisms and the Influence of Androgen Deprivation Therapy on Osteopenia—A Pilot Study

“…Lower PSA levels and larger-sized prostates in men with higher body mass index (BMI) make biopsy of prostate less accurate for finding an existing cancer (Buschemeyer and Freedland, 2007). Recent data suggest that obesity might be associated with increased risk of malignancy (Hekal and Ibrahiem, 2010) and that it is less common in benign prostate disease. Many reports have shown an inverse relationship between PSA and BMI; Hekal and Ibrahiem (2010) designed an inverse PSA-BMI equation to enhance the sensitivity of PSA marker in obese patients.…”

“…Recent data suggest that obesity might be associated with increased risk of malignancy (Hekal and Ibrahiem, 2010) and that it is less common in benign prostate disease. Many reports have shown an inverse relationship between PSA and BMI; Hekal and Ibrahiem (2010) designed an inverse PSA-BMI equation to enhance the sensitivity of PSA marker in obese patients.…”