Tag Archive for: prostate volume

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Article of the Month: The Metabolic Syndrome & the Prostate

Every Month, the Editor-in-Chief selects an Article of the Month from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

If you only have time to read one article this week, it should be this one.

Association between metabolic syndrome and intravesical prostatic protrusion in patients with benign prostatic enlargement and lower urinary tract symptoms (MIPS Study)

Giorgio I. Russo*, Federica Regis*, Pietro Spatafora, Jacopo Frizzi, Daniele Urzı*, Sebastiano Cimino*, Sergio Serni, Marco Carini, Mauro Gacci† and Giuseppe Morgia*

 

*Urology Section, Department of Surgery, University of Catania, Catania, Italy, and Department of Urology, University of Florence, Florence, Italy

 

Abstract

Objective

To investigate the association between metabolic syndrome (MetS) and morphological features of benign prostatic enlargement (BPE), including total prostate volume (TPV), transitional zone volume (TZV) and intravesical prostatic protrusion (IPP).

Patients and Methods

Between January 2015 and January 2017, 224 consecutive men aged >50 years presenting with lower urinary tract symptoms (LUTS) suggestive of BPE were recruited to this multicentre cross‐sectional study. MetS was defined according to International Diabetes Federation criteria. Multivariate linear and logistic regression models were performed to verify factors associated with IPP, TZV and TPV.

Results

Patients with MetS were observed to have a significant increase in IPP (P < 0.01), TPV (P < 0.01) and TZV (P = 0.02). On linear regression analysis, adjusted for age and metabolic factors of MetS, we found that high‐density lipoprotein (HDL) cholesterol was negatively associated with IPP (r = −0.17), TPV (r = −0.19) and TZV (r = −0.17), while hypertension was positively associated with IPP (r = 0.16), TPV (r = 0.19) and TZV (r = 0.16). On multivariate logistic regression analysis adjusted for age and factors of MetS, hypertension (categorical; odds ratio [OR] 2.95), HDL cholesterol (OR 0.94) and triglycerides (OR 1.01) were independent predictors of TPV ≥ 40 mL. We also found that HDL cholesterol (OR 0.86), hypertension (OR 2.0) and waist circumference (OR 1.09) were significantly associated with TZV ≥ 20 mL. On age‐adjusted logistic regression analysis, MetS was significantly associated with IPP ≥ 10 mm (OR 34.0; P < 0.01), TZV ≥ 20 mL (OR 4.40; P < 0.01) and TPV ≥ 40 mL (OR 5.89; P = 0.03).

Conclusion

We found an association between MetS and BPE, demonstrating a relationship with IPP.

Editorial: The metabolic syndrome and the prostate

The metabolic syndrome has been known for ~80 years 1 and is important to both urologists and their patients because of a two‐fold increase in the relative risk of atherosclerotic cardiovascular disease‐related events and a five‐fold increase for developing Type 2 diabetes as compared to people without the syndrome. Abdominal obesity is well known to be an important underlying risk factor for precipitating the syndrome and obesity is also known to markedly increase the risk for developing BPH and its symptoms 2. There are other associations that may be relevant here including an association between a lack of physical activity and the severity of LUTS 3, and a close correlation between the degree of prostatic and systemic inflammation and the degree of LUTS 4. Systemic inflammation is implicated in the metabolic syndrome with pro‐inflammatory cytokines due to the adipose tissue load, such as C‐reactive protein, tumour necrosis factor α and interleukin 6, being involved in causing the insulin resistance, which is a diagnostic feature of this condition 5.

The current study connects the metabolic syndrome with an anatomical feature of benign prostatic enlargement (BPE), namely intravesical prostatic protrusion (IPP) 6. Each of the diagnostic features of metabolic syndrome was examined separately such as reduced high‐density lipoprotein (HDL)‐cholesterol and raised triglycerides. Hypertriglyceridaemia is due to an overproduction of very‐low‐density lipoprotein (VLDL) by the liver and a reduction of lipoprotein lipase in peripheral tissues, and reflects the insulin resistant condition responsible for the metabolic syndrome 5. In this study, high triglyceride levels were an independent predictor of a total prostatic volume (TPV) of >40 mL. The other major lipoprotein abnormality in metabolic syndrome is a reduction in HDL‐cholesterol levels, which is due to both a decrease in the cholesterol content of this lipoprotein and an increase in its clearance from the circulation. In this study by Russo et al. 6, HDL levels were negatively associated with IPP and both total and transition zone volumes, and they postulate that these associations may be mediated by the effect of dyslipidaemia on prostate cells and prostatic inflammation.

Hypertension is another diagnostic feature that the authors address. There is increased renal sodium reabsorption, increased activity of the sympathetic nervous system, and vasoconstriction related to an increase in fatty acids in this syndrome. Hypertension, defined as systolic ≥135 mmHg, diastolic ≥85 mmHg or on current treatment, was positively associated with IPP and also associated with a TPV of ≥40 mL and a transitional zone volume of ≥20 mL in this study 6. Waist circumference and fasting glucose were not as strongly related to the features of BPH but ultimately are key drivers of the metabolic syndrome and management of these features is a cornerstone of the management of the whole condition.

Lifestyle and dietary interventions can address many of the aspects of this insulin‐resistant state with medical management of the metabolic features being used to supplement these. The same interventions are also successful in decreasing LUTS 3, which should not be surprising given the above. The longstanding aphorism that ‘heart healthy is prostate healthy’ appears to not only apply to the treatment of prostate cancer but also to that of BPH and urologists remain in an important position to identify men at significant risk.

Peter J. Gilling
Urology, Bay of Plenty District Health Board Clinical SchoolTauranga, New Zealand

 

References
  • Alberti KG, Zimmet P, Shaw J, IDF Epidemiology Task Force Consensus Group. The metabolic syndrome–a new worldwide definitionLancet 2005366: 1059–62

 

  • Parsons JK, Sarma AV, McVary K, Wei JT. Obesity and benign prostatic hyperplasia: clinical connections, emerging etiological paradigms and future directionsJ Urol 2013189 (Suppl.): S102–6.

 

  • Fowke JH, Phillips S, Koyama T et al. Association between physical activity, lower urinary tract symptoms (LUTS) and prostate volumeBJU Int 2013111: 122–8

 

  • Burris MB, Cathro HP, Kowalik CG et al. Lower urinary tract symptom improvement after radical prostatectomy correlates with degree of prostatic inflammationUrology 201483: 186–90

 

  • Eckel RH, Grundy SM, Zimmet PZ. The metabolic syndromeLancet 2005365: 1415–28

 

  • Russo GI, Regis F, Spatafora P et al. Association between metabolic syndrome and intravesical prostatic protrusion in patients with benign prostatic enlargement and lower urinary tract symptoms (MIPS Study)BJU Int 2018121: 799–804.

 

Article of the Week: Effect of MetS on serum PSA levels is concealed by enlarged prostate

Every Week the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

Finally, the third post under the Article of the Week heading on the homepage will consist of additional material or media. This week we feature a video discussing the paper.

If you only have time to read one article this week, it should be this one.

Actual lowering effect of metabolic syndrome on serum prostate-specific antigen levels is partly concealed by enlarged prostate: results from a large-scale population-based study

Sicong Zhao*, Ming Xia*, Jianchun Tang† and Yong Yan*

 

*Department of Urology, and Department of Cardiology, Beijing Shijitan Hospital, Capital Medical University, Beijing, China

 

Abstract

Objectives

To clarify the lowering effect of metabolic syndrome (MetS) on serum prostate-specific antigen (PSA) levels in a Chinese screened population.

Subjects and Methods

A total of 45 540 ostensibly healthy men aged 55–69 years who underwent routine health check-ups at Beijing Shijitan Hospital between 2008 and 2015 were included in the study. All the men underwent detailed clinical evaluations. PSA mass density was calculated (serum PSA level × plasma volume ÷ prostate volume) for simultaneously adjusting plasma volume and prostate volume. According to the modified National Cholesterol Education Programme–Adult Treatment Panel (NCEP-ATP) III criteria, patients were dichotomized by the presence of MetS, and differences in PSA density and PSA mass density were compared between groups. Linear regression analysis was used to evaluate the effect of MetS on serum PSA levels.

Results

When larger prostate volume in men with MetS was adjusted for, both PSA density and PSA mass density in men with MetS were significantly lower than in men without MetS, and the estimated difference in mean serum PSA level between men with and without MetS was greater than that before adjusting for prostate volume. In the multivariate regression model, the presence of MetS was independently associated with an 11.3% decline in serum PSA levels compared with the absence of MetS. In addition, increasing number of positive MetS components was significantly and linearly associated with decline in serum PSA levels.

Conclusion

The actual lowering effect of MetS on serum PSA levels was partly concealed by the enlarged prostate in men with MetS, and the presence of MetS was independently associated with lower serum PSA levels. Urologists need to be aware of the effect of MetS on serum PSA levels and should discuss this subject with their patients.

Editorial: Anomalous observation with regard to PCa in cancer research

In science, reports showing data deviating from what is expected are called anomalous observations. Metabolic syndrome (MetS) is a promoter of cancer at almost all sites [1]; however, when it comes to prostate cancer (PCa), a series of reports have been published showing an inverse relationship between MetS and its aspects and incident PCa. This lack of coherence in cancer research seriously hampers efforts to fight cancer disorders. It is therefore crucial to find an explanation for this incoherence.

In the search for a reasonable explanation for this anomalous observation, a hypothesis has been formulated, based on the study by Häggström et al. [2], and stating that the PSA-driven diagnostic procedure in PCa, which creates low-stage incident PCa material, is the culprit. The PSA-driven diagnostic procedure introduces several bias mechanisms, which tend to protect men with MetS from being diagnosed with PCa. Thus, men with MetS and its aspects are under-represented in PCa populations generated by PSA-driven diagnostics, thereby creating a distorted incident PCa population. This hypothesis also predicts that high-stage PCa, as well as non-localized and lethal PCa, are not subject to these bias mechanisms, as a minor reduction in the PSA level is of no importance for the PCa diagnosis at these high PSA levels. Finally, the hypothesis predicts that the link between MetS and incident PCa is stage-dependent. A study testing this hypothesis is now in progress.

Several studies have reported that men with MetS had lower PSA levels compared with men without MetS. Zhao et al. [3] address this specific question in this issue of BJUI and confirm that the presence of MetS was independently associated with a lower PSA level and that the enlarged prostate gland, which is an aspect of MetS, partly concealed an even greater PSA level reduction [3]. The findings indicate that a bias mechanism inverses the link between MetS and incident PCa and support the above-mentioned hypothesis.

In short, the following bias mechanisms have been described. MetS is associated with greater body fat with increased aromatase activity, resulting in a reduced testosterone level, which, in turn, is related to a reduced PSA level, as the production of PSA is under androgen control. Another possible bias mechanism, leading to men with MetS being diagnosed less often with PCa, is that these men are more likely to be obese. It is well established that men with a higher BMI also have larger plasma volumes and therefore have greater haemodilution of the PSA production, resulting in a lower PSA level. This means that incident PCa is diagnosed less often in men with MetS, as their PSA level is lower. MetS is also associated with an enlarged prostate gland volume, which means that fewer incident PCas are diagnosed, given the same tumour volume and the same number of biopsies. Another bias mechanism is that a high proportion of men with high socio-economic status undergo PSA testing in the PSA era. It is well established that men with a high socio-economic status have a lower prevalence of MetS and therefore have higher PSA levels, as indicated by the present report in the BJUI [3], and an elevated risk of PCa. Thus, multiple bias mechanisms seem to conceal low-stage PCa in the PSA era.

If it could be confirmed that the negative relationship between MetS and incident PCa is a spurious observation as a result of bias mechanisms, this would open the door for the MetS hypothesis regarding the promotion of multiple cancer disorders. This door has previously been closed by findings in a series of reports of an inverse relationship between MetS and its aspects and incident prostate cancer. Furthermore, this could lead to increased efforts to fight the metabolic aberrations of MetS. It is now well established that MetS and its aspects could be reduced by changes in lifestyle, including physical activity and diet. The most convincing evidence of the effect of diet on MetS comes from studies involving decreased intake of carbohydrates and increased intake of unsaturated fats. Recently, leading authorities in nutrition, endocrinology and metabolism presented a critical review and concluded that carbohydrate restriction is the single most effective intervention to reduce all features of MetS [4]. Another review concluded that carbohydrate restriction is one of the few common interventions that target all features of MetS [5]. This conclusion has recently been confirmed in a meta-analysis by Mansoor et al. [6].

In conclusion, new knowledge challenges the anomalous observation of PCa showing a negative relationship between MetS and PCa. The credibility of the hypothesis that MetS is an important promoting factor for cancer at almost all sites is strengthened. MetS could be treated effectively with a low carbohydrate and high fat diet.

Jan Hammarsten, MD, PhD
Department of Urology, Institute of Clinical SciencesUniversity of Gothenburg, Gothenburg, Sweden

 

 

References

 

1 Esposito K, Chiodini P, Colao AM et al. Metabolic syndrome and risk of cancer. Diabetes Care 2012; 35: 240211 

 

2Haggstrom C, Stocks T, Ulmert D et al. Prospective study on metabolic factors and risk of prostate cancer. Cancer 2012; 118: 6199206

 

3 Zhao S, Xia M, Tang J et al. The actual lowering effect of metabolic syndrome on serum prostate-specic antigen levels is partly concealed by enlarged prostate: results from large-scale population-based study. BJU Int 2017; 120: 4829

 

4 Feinman RD, Pogozelski WK, Astrup A et al. Dietary carbohydrate restriction as the rst approach in diabetes management: critical review and evidence base. Nutrition 2015;31: 113

 

5 Accurso A, Bernstein RK, Dahlqvist A et al. Dietary carbohydrate restriction in type 2 diabetes mellitus and metabolic syndrome: time for critical appraisal. Nutrition & Metabolism 2008; 5: 9

 

6 Mansoor N, Vinknes UJ , Veierod MB et al. Effects of low-carbohydrate diets v. low fat diets on body weight and cardiovascular risk factors: meta-analysis of randomized controlled trials. Br J Nutrition 2016; 115: 4667

 

Video: Effect of MetS on serum PSA levels is concealed by enlarged prostate

Actual lowering effect of metabolic syndrome on serum prostate-specific antigen levels is partly concealed by enlarged prostate: results from a large-scale population-based study

Sicong Zhao*, Ming Xia*, Jianchun Tang† and Yong Yan*

 

*Department of Urology, and Department of Cardiology, Beijing Shijitan Hospital, Capital Medical University, Beijing, China

 

Abstract

Objectives

To clarify the lowering effect of metabolic syndrome (MetS) on serum prostate-specific antigen (PSA) levels in a Chinese screened population.

Subjects and Methods

A total of 45 540 ostensibly healthy men aged 55–69 years who underwent routine health check-ups at Beijing Shijitan Hospital between 2008 and 2015 were included in the study. All the men underwent detailed clinical evaluations. PSA mass density was calculated (serum PSA level × plasma volume ÷ prostate volume) for simultaneously adjusting plasma volume and prostate volume. According to the modified National Cholesterol Education Programme–Adult Treatment Panel (NCEP-ATP) III criteria, patients were dichotomized by the presence of MetS, and differences in PSA density and PSA mass density were compared between groups. Linear regression analysis was used to evaluate the effect of MetS on serum PSA levels.

Results

When larger prostate volume in men with MetS was adjusted for, both PSA density and PSA mass density in men with MetS were significantly lower than in men without MetS, and the estimated difference in mean serum PSA level between men with and without MetS was greater than that before adjusting for prostate volume. In the multivariate regression model, the presence of MetS was independently associated with an 11.3% decline in serum PSA levels compared with the absence of MetS. In addition, increasing number of positive MetS components was significantly and linearly associated with decline in serum PSA levels.

Conclusion

The actual lowering effect of MetS on serum PSA levels was partly concealed by the enlarged prostate in men with MetS, and the presence of MetS was independently associated with lower serum PSA levels. Urologists need to be aware of the effect of MetS on serum PSA levels and should discuss this subject with their patients.

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