Endogenous Circulating Sex Hormone Concentrations and Colon Cancer Risk in Postmenopausal Women: A Prospective Study and Meta-Analysis

Background Observational studies have consistently reported that postmenopausal hormone therapy use is associated with lower colon cancer risk. However, epidemiological studies examining the associations between circulating concentrations of endogenous estrogens and colorectal cancer have reported inconsistent results. Methods We investigated the associations between circulating concentrations of estrone, estradiol, free estradiol, testosterone, free testosterone, androstenedione, dehydroepiandrosterone (DHEA), progesterone, and sex hormone binding globulin (SHBG) with colon cancer risk in a nested case–control study of 1,028 postmenopausal European women (512 colon cancer cases, 516 matched controls) who were non-current users of exogenous hormones at blood collection. Multivariable conditional logistic regression models were used to compute odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the association between circulating sex hormones and colon cancer risk. We also conducted a dose-response meta-analysis of prospective studies of circulating estrone and estradiol with colorectal, colon, and rectal cancer risk in postmenopausal women. All statistical tests were 2-sided. Results In the multivariable model, a non-statistically significant positive relationship was found between circulating estrone and colon cancer risk (OR per log2-1 unit increment = 1.17, 95%CI = 1.00–1.38; ORquartile4-quartile1 = 1.33, 95%CI = 0.89–1.97, Ptrend = 0.20). Circulating concentrations of estradiol, free estradiol, testosterone, free testosterone, androstenedione, DHEA, progesterone, and SHBG were not associated with colon cancer risk. In the dose-response meta-analysis, no clear evidence of associations were found between circulating estradiol, and estrone concentrations with colorectal, colon, and rectal cancer risk. Conclusion Our observational and meta-analysis results do not support an association between circulating concentrations of endogenous sex hormones and colon or rectal cancer in postmenopausal women.

Lack of Association Between ACE2 Expression and Serum Testosterone Concentrations in Peripheral Mononuclear Cells in Males

Background: Male sex is a risk factor for developing severe COVID-19 illness, hospitalization, and mortality. It is possible that the male sex hormone, testosterone, contributes to the morbidity from COVID-19. SARS-CoV2 viruses use cell membrane protein Angiotensin-Converting Enzyme 2 (ACE2) receptor and undergo S protein priming by the Type II Transmembrane Serine Protease (TMPRSS2) to enter the cells. Hence, the expression level of ACE2 and TMPRSS2 may affect disease susceptibility and possible severity. TMPRSS2 is regulated by the androgen receptor. We, therefore, examined if an association exists between serum testosterone concentrations and ACE2 or TMPRSS2 expression level in men. Methods: We analyzed fasting serum samples and peripheral blood mononuclear cells (MNC) from 42 men. Total and free testosterone and estradiol were measured by liquid chromatography/equilibrium dialysis. Sex hormone binding globulin (SHBG) was measured by chemiluminescence. mRNA was prepared from MNC. Quantitative RT-PCR was conducted using commercially available, pre-designed TaqMan primers and probes targeting ACE2. The ACE2 relative level was calculated after normalization to beta Actin and GAPDH, with lowest ACE2 level being set to 1. Results: Subjects’ age ranged from 20 to 65 years. Type 2 diabetes was present in 74% of the men and the mean HbA1 was 7.2±1.6% (mean ± S.D.). Fifteen subjects had subnormal free testosterone (<50 pg/ml). Compared to the 27 subjects with normal free testosterone, they were older (49±12 vs 40±13 years, p=0.03) but had similar BMI (36±10, 35±10 kg/m2, p=0.71). As expected, they had lower total testosterone (Median [25th, 75th percentile]; 222 [171-266] vs 431 [335, 618] ng/dl, p<0.001) and free testosterone concentrations (39 [21, 44] vs 72 [59, 92], p<0.001). Total estradiol was also lower in this group (19±1 vs 29±13 pg/ml, p=0.03) but free estradiol (0.44±0.33 vs 0.56±0.34 pg/ml, p=0.44) and SHBG (27 [19, 33] vs 30 [21, 39] nmol/L, p=0.52) were similar. Quantitative PCR data showed there was a large inter-individual variation of ACE2 expression level, up to 15-fold difference. Average ACE2 level did not differ between subnormal and normal testosterone groups (3.4 [2.7, 5.0] vs 3.9 [2.5, 5.7] arbitrary units). ACE2 expression was not related to free testosterone (r=0.11), free estradiol (r=0.18) or sex hormone binding globulin (r=0.15) on linear regression analyses (p>0.30 for all). ACE2 expression was also not related to age (r= -0.15, p=0.34), BMI (r= -0.2, p=0.23) or presence of diabetes. We were not able to detect a significant expression of TMPRSS2 in MNC. Conclusion: Our results do not support a role for testosterone or estradiol as regulators of ACE2 expression in peripheral blood MNC in males.

Plasma sex hormones and risk of conventional and serrated precursors of colorectal cancer in postmenopausal women

Background Sex hormones have been suggested to play a role in colorectal cancer (CRC), but their influence on early initiation of CRC remains unknown. Methods We retrospectively examined the associations with risk of CRC precursors, including conventional adenomas and serrated polyps, for plasma estrone, estradiol, free estradiol, testosterone, free testosterone, sex hormone-binding globulin (SHBG), and the ratio of estradiol to testosterone among 5404 postmenopausal women from the Nurses’ Health Study I and II. Multivariable logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI). Given multiple testing, P < 0.005 was considered statistically significant. Results During 20 years of follow-up, we documented 535 conventional adenoma cases and 402 serrated polyp cases. Higher concentrations of SHBG were associated with lower risk of conventional adenomas, particularly advanced adenomas (multivariable OR comparing the highest to the lowest quartile, 0.40, 95% CI 0.24–0.67, P for trend < 0.0001). A nominally significant association was found for SHBG with lower risk of large serrated polyps (≥ 10 mm) (OR, 0.47, 95% CI 0.17–1.35, P for trend = 0.02) as well as free estradiol and free testosterone with higher risk of conventional adenomas (OR, 1.54, 95% CI 1.02–2.31, P for trend = 0.03 and OR, 1.33, 95% CI 0.99–1.78, P for trend = 0.03, respectively). Conclusions The findings suggest a potential role of sex hormones, particularly SHBG, in early colorectal carcinogenesis.

MON-382 Bone Quality and Strength in Obese Men with Type 2 Diabetes Mellitus Are Impaired and Negatively Influenced by Adiposity

Background: Obesity and type 2 diabetes mellitus (T2DM) are both associated with normal to above average bone mineral density (BMD) but increased risk of fragility fractures. The impact of T2DM on bone mechanical and microarchitectural features in the obese population is unknown. We hypothesize that obese diabetics have lower bone quality compared to obese nondiabetic individuals. In this study, we investigated the microarchitectural features and mechanical properties of bone of obese men with and without T2DM along with the independent predictors of bone strength. Methods: Ninety-seven obese men (BMI &gt;30) aged 35-65 years-old of which 38 had T2DM were included in the analysis. BMD and body composition were evaluated by DXA and bone microarchitecture of the tibia by high-resolution peripheral quantitative computed tomography. Bone strength was assessed by micro finite element analysis-derived parameters as failure load (f. load) and stiffness. Serum testosterone and estradiol were measured by LC-MS. Serum SHBG, osteocalcin (OCN), C-telopeptide (CTx) and sclerostin (SCL) were measured by ELISA. Results: OCN is lower in obese men with T2DM compared to those without T2DM (4.8 ± 2.8 vs 6.2 ± 2.6 ng/mL p=0.03, respectively), with also a trend for reduced CTx and SCL in the former. BMD at all sites was reduced in obese men with T2DM, but there were no differences in body composition. Obese diabetics also had lower tibial total volumetric BMD (vBMD) (p=0.04) and trabecular vBMD (p=0.01) with greater trabecular spacing (p=0.005). F. load (13.3 ± 2.1 vs 14.5 ± 2.3 kN, p= 0.02) and stiffness (24.7± 4.2 vs 27 ± 4.6 kN/mm, p=0.02) were reduced in men with T2DM relative to men without T2DM, respectively. F. load and stiffness were positively correlated with BMD at all sites, fat free mass (FFM), lean mass, free testosterone, free estradiol and SCL, but negatively correlated with % total body fat and visceral adipose tissue (VAT). FFM, BMD of the total hip, femoral neck and lumbar spine and free testosterone were significant independent predictors of bone strength in the entire group (model: R2: 65.01 p&lt; 0.0001 for f. load and model: R2:63.21 p &lt; 0.0001 for stiffness), whereas age and lumbar spine BMD were found to be independent predictors of bone strength in the non-diabetic group (model R2: 54.6 p&lt; 0.0001 for both f. load and stiffness). Analysis limited to the diabetic subgroup showed that BMD at the femoral neck and total hip, % total body fat, VAT volume, SCL and free estradiol were independent predictors of bone strength (model: R2: 88.4 and p&lt; 0.0001 for f. load and model: R2: 85.3 and p&lt;0.0001 for stiffness). Interleukin-6 was comparable between groups. Conclusions: Obese men with T2DM have lower bone formation and impaired bone quality and strength compared to those without T2DM. In addition to BMD and gonadal hormones, adiposity is an important predictor of bone strength in obese men with T2DM.

Age-Specific Serum Total and Free Estradiol Concentrations in Healthy Men in US Nationally Representative Samples

Purpose To report age-specific serum estradiol concentration in nonsmoking, lean US men without comorbidities. We provide concentrations from 30 and 15 to 20 years ago given previously described declines in serum estradiol in US men over time. Methods We used data from the Third National Health and Nutrition Examination Survey (NHANES III; 1988 to 1991) and continuous NHANES (1999 to 2004). Serum estradiol and SHBG were previously measured by competitive electrochemiluminescence immunoassays. Free estradiol was estimated from estradiol, SHBG, and albumin. By age, we calculated median concentrations overall and for nonsmoking, lean (body mass index <25 kg/m2 and waist <102 cm) men without diabetes, cardiovascular disease, or cancer. Results Overall, respective total estradiol medians for men ages 20 to 39, 40 to 59, and ≥60 years old were 37.0, 33.9, and 33.5 pg/mL in NHANES III and 31.3, 30.5, and 27.0 pg/mL in continuous NHANES. In nonsmoking, lean men without comorbidities, respective total estradiol medians were 32.0, 32.1, and 32.0 pg/mL in NHANES III and 29.1, 22.7, and 26.1 pg/mL in continuous NHANES. Overall, respective free estradiol medians were 0.82, 0.72, and 0.64 pg/mL in NHANES III and 0.67, 0.61, and 0.47 pg/mL in continuous NHANES. In nonsmoking, lean men without comorbidities, respective free estradiol medians were 0.64, 0.67, and 0.62 pg/mL in NHANES III and 0.58, 0.42, and 0.40 pg/mL continuous NHANES. Conclusion We report US nationally representative serum estradiol concentrations in healthy men, which could be used for targeting estradiol during testosterone supplementation and for general good health.

Coffee consumption and plasma biomarkers of metabolic and inflammatory pathways in US health professionals

ABSTRACT Background Coffee consumption has been linked to lower risk of various health outcomes. However, the biological pathways mediating the associations remain poorly understood. Objectives The aim of this study was to assess the association between coffee consumption and concentrations of plasma biomarkers in key metabolic and inflammatory pathways underlying common chronic diseases. Methods We investigated the associations of total, caffeinated, and decaffeinated coffee consumption with 14 plasma biomarkers, including C-peptide, insulin-like growth factor 1 (IGF-1), IGF binding protein (IGFBP) 1, IGFBP-3, estrone, total and free estradiol, total and free testosterone, sex hormone–binding globulin (SHBG), total adiponectin, high-molecular-weight (HMW) adiponectin, leptin, C-reactive protein (CRP), interleukin 6 (IL-6), and soluble tumor necrosis factor receptor 2 (sTNFR-2). Data were derived from 2 cohorts of 15,551 women (Nurses’ Health Study) and 7397 men (Health Professionals Follow-Up Study), who provided detailed dietary data before blood draw and were free of diabetes, cardiovascular disease, or cancer at the time of blood draw. Multivariable linear regression was used to calculate the percentage difference of biomarker concentrations comparing coffee drinkers with nondrinkers, after adjusting for a variety of demographic, clinical, and lifestyle factors. Results Compared with nondrinkers, participants who drank ≥4 cups of total coffee/d had lower concentrations of C-peptide (−8.7%), IGFBP-3 (−2.2%), estrone (−6.4%), total estradiol (−5.7%), free estradiol (−8.1%), leptin (−6.4%), CRP (−16.6%), IL-6 (−8.1%), and sTNFR-2 (−5.8%) and higher concentrations of SHBG (5.0%), total testosterone (7.3% in women and 5.3% in men), total adiponectin (9.3%), and HMW adiponectin (17.2%). The results were largely similar for caffeinated and decaffeinated coffee. Conclusion Our data indicate that coffee consumption is associated with favorable profiles of numerous biomarkers in key metabolic and inflammatory pathways. This trial was registered at clinicaltrials.gov as NCT03419455.