Age, BMI influence zonal growth pattern of prostate

The growth rates of transition and peripheral zones of the prostate vary, according to a study. Body mass index (BMI) and transition zone index (TZI) contribute to peripheral zone growth rate, while use of 5-alpha reductase inhibitor (5ARI) reduces the transition zone growth rate.

“As men age, the prostate continues to grow on average 2.5 percent per year,” the researchers said. “While the variable growth rate of the total prostate gland is recognized, the growth rate of different prostate zones remains largely unclear.”

This study was conducted to assess growth patterns of the prostate zones and to identify clinical parameters that contribute to the zonal growth rates.

The researchers retrospectively obtained prostate magnetic resonance imaging (MRI) data and clinical information on 156 patients with at least three prostate MRIs between 2003 and 2018. They also measured and analysed various prostate zonal volumes, as well as the outcome using linear regression.

Prostate growth rates differed according to BMI, TZI, the prostate zone, and 5ARI use. The peripheral zone volume growth rates increased with age and peaked at age 60‒70 years (p=0.047), while the transition zone volume showed continuous growth without a peak through all ages.

BMI (p=0.026) and TZI (p<0.001) both contributed to the growth rate of the peripheral zone, but not to the transition growth rate.

Use of 5ARI significantly correlated with the reduction in the transition zone growth rate (p=0.033), but not in the peripheral zone. Furthermore, patients with TZI >60 percent exhibited the most significant decrease in the transition zone growth rate while taking 5ARI (p<0.001).