This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.

/pdf/aging-and-the-male-reproductive-system-5edbn74htz.pdf

Aging and the Male Reproductive System.

Previous studies established a possible link among hyperhomocysteinemia (HHcy), dyslipidemia, and atherosclerosis. However, there was limited epidemic data concerning the relation between HHcy and lipid profiles, especially in community-based Chinese populations. This study aim to investigate the association of plasma homocysteine (Hcy) level with lipid profiles in a Chinese community-based population without lipid-lowering treatment. A total of 4660 Chinese subjects from a cohort of the Shijingshan district in Beijing were included in the analysis. Plasma total Hcy, serum lipid files including total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) as well as relevant metabolic risk factors were measured. Multivariate regression models adjusting for age, gender, smoking, drinking, physical activity, vitamin B supplement, body mass index, fasting blood glucose level, serum creatinine, systolic and diastolic blood pressure were used to evaluate associations of Hcy and lipid profiles. Subjects were 56.75 ± 8.91 years old, and 38.15% were male. Median (IQR) Hcy was 11.98 (10.00–14.93) μmol/L, and 24.4% had HHcy (defined as Hcy ≥ 15 μmol/L). Mean (SD) baseline TC was 5.34 ± 0.98 mmol/L, LDL-C was 3.27 ± 0.81 mmol/L, and HDL-C was 1.43 ± 0.38 mmol/L. Median (IQR) of TG was 1.28 (0.91–1.85) mmol/L. In multivariable linear-regression analyses, lnHcy (ln transformation for Hcy) level was positively associated with lnTG (adjusted β = 0.075, SE = 0.021, P = 0.001). Using Hcy < 15 μmol/L as a reference, HHcy was independently associated with both lnTG (adjusted β = 0.056, SE = 0.020, P = 0.004) and lnHDL (adjusted β = −0.018, SE = 0.009, P = 0.038). In multivariable logistic-regression analyses, HHcy was associated with increasing risk of low HDL-C (HDL-C < 1.04 mmol/L; adjusted odds ratio [OR] =1.406, 95% confidence interval [CI]: 1.143 – 1.728, P = 0.001) and hypertriglyceridemia (TG ≥ 1.7 mmol/L; adjusted OR = 1.293, 95% CI: 1.096–1.524, P = 0.002) after adjusting the confounders. However, there were no significant associations between Hcy and TC or LDL-C. The present study showed that HHcy was independently associated with hypertriglyceridemia and low levels of HDL-C, which provides evidence that Hcy levels might affect HDL-C and TG metabolism.

/pdf/relationship-between-plasma-homocysteine-level-and-lipid-3m4kr6hl9p.pdf

Relationship between plasma homocysteine level and lipid profiles in a community-based Chinese population.

Vitamin D may play a role in glucose metabolism. A low vitamin D level has been associated with increased risk of diabetes mellitus, but the association has not been confirmed in Asians. Our objective was to examine the association of serum 25-hydroxyvitamin D [25(OH)D] levels with insulin resistance and diabetes mellitus in Korean adults based on a large population-based survey. Cross-sectional analyses were carried out on 5787 Korean adults (2453 men and 3334 women) who were 20 y or older and participated in the Fourth Korea NHANES conducted in 2008. Diabetes mellitus was defined as fasting plasma glucose ≥7 mmol/L or current use of oral hypoglycemic agents or insulin. Insulin resistance was estimated by homeostatic model assessment for insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI). Compared to individuals with a sufficient serum 25(OH)D concentration ≥75 nmol/L, the OR (95% CI) for diabetes mellitus were 1.73 (1.09-2.74), 1.30 (0.91-1.84), and 1.40 (0.99-1.98) for serum 25(OH)D concentrations <25, 25 to <50, and 50 to <75 nmol/L, respectively, after multiple adjustments (P-trend < 0.0001). Furthermore, the serum 25(OH)D level was inversely associated with HOMA-IR (β = -0.061; P = 0.001) and positively associated with QUICKI (β = 0.059; P = 0.001) in overweight or obese participants. In conclusion, a low serum vitamin D concentration is associated with a high risk of diabetes mellitus in Korean adults and the concentration is inversely associated with insulin resistance in those who are overweight or obese.

https://ir.ymlib.yonsei.ac.kr/bitstream/22282913/94141/1/T201103286.pdf

Low serum vitamin D is associated with high risk of diabetes in Korean adults

Multiple changes occur across various endocrine systems as an individual ages. The understanding of the factors that cause age-related changes and how they should be managed clinically is evolving. This statement reviews the current state of research in the growth hormone, adrenal, ovarian, testicular, and thyroid axes, as well as in osteoporosis, vitamin D deficiency, type 2 diabetes, and water metabolism, with a specific focus on older individuals. Each section describes the natural history and observational data in older individuals, available therapies, clinical trial data on efficacy and safety in older individuals, key points, and scientific gaps. The goal of this statement is to inform future research that refines prevention and treatment strategies in age-associated endocrine conditions, with the goal of improving the health of older individuals.

Hormones and Aging: An Endocrine Society Scientific Statement.

Aim. To investigate the epidemiology, etiology, and severity of acute pancreatitis (AP) in urban and suburban areas of Shanghai in 2011 and 2016. Methods. A retrospective study of patients admitted to Shanghai General Hospital (urban and suburban campuses) with AP in 2011 and 2016 was undertaken. Patients were divided into acute biliary pancreatitis (ABP), hypertriglyceridemic pancreatitis (HTGP), alcoholic pancreatitis, and pancreatitis of other causes according to etiology. Severity of AP was divided into mild AP (MAP), moderately severe AP (MSAP), and severe AP (SAP). Results. AP patients in the suburban area increased more rapidly than those in the urban area. The mean onset age of AP in the urban area in 2016 was older than that in the suburban area ( ). The suburban patients in 2016 have significantly younger mean onset age than those in 2011 ( ). HTGP incidence in suburban patients increased from 2011 to 2016, which changed little in the urban area. Urban females were more likely to develop HTGP than suburban ones in 2011, which reversed in 2016. As to the male patients, the incidence of HTGP increased in both urban and suburban areas. Nonelderly (<60 years old) patients had higher HTGP incidence than elderly ones in both 2011 and 2016. The descending trend of SAP in the suburban area was more obvious than that in the urban area. The length of hospitalization decreased from 2011 to 2016, especially in SAP patients. Conclusions. AP patients increased more rapidly in the suburban area of Shanghai with younger onset age. The incidence of HTGP increased significantly in the suburban area, reminding of the prevention and screening of HTG.

/pdf/epidemiology-and-etiology-of-acute-pancreatitis-in-urban-and-50pcomum2d.pdf

Epidemiology and Etiology of Acute Pancreatitis in Urban and Suburban Areas in Shanghai: A Retrospective Study.

To assess the 9-year changes of the incidence and characteristics of metabolic syndrome (MetS) in Chinese community under the background of dramatically changed environment. Two cross-sectional surveys of the general population were carried out in 2005 and 2014 in Dengmin and Hongnan villages of Fengcheng community, a newly formed urban community from rural area 10 years ago. All permanent adult residents aged 18–80 without active malignant tumors and pregnancy were invited to attend the study. They participated in clinical examinations for anthropometric and blood pressure measurements. Fasting blood samples were drawn for analysis of lipids and glucose. Presence of MetS was defined based on the IDF/AHA harmonized criteria. MetS z-score was calculated to evaluate the degree of total metabolic disorder. A total of 1042 subjects in 2005 and 1053 subjects in 2014 were included in the final analysis. The participants were stratified by gender. The incidence of MetS was higher in 2014 than 2005 in both genders (female, 48.28 vs 31.61 %; male, 41.12 vs 26.30 %; p value, both <0.001). Of the five MetS components, the FBG and TG levels were higher in 2014 than 2005 in both gender, however, the SBP and DBP values were even lower in 2014 than 2005. The differences of FBG, blood pressure and lipid levels between 2005 and 2014 still exist after ruling out recognized diabetic, hypertensive and dyslipidemic subjects, individually. In MetS subjects, MetS z-score showed the whole metabolic profile get worse in 2014 than 2005 in both sex (female, 1.97 ± 2.53 vs 1.74 ± 2.29; male, 2.51 ± 2.79 vs 1.01 ± 2.38. both P < 0.001). Using 3 abnormal components as a combination, we found the frequency of different kinds of combination also changed in MetS subjects. In female, the combination of WC + BP + HDL disorder decreased from 29.7 % (2005) to 11.0 % (2014) and WC + FBG + BP disorder became the most popular phenotype (18.8 %) in 2014. The dramatically changed environments have extensive influence on metabolic parameters of local residents. More targeted measures need to be taken to meet the serious challenges of metabolic diseases. Trial registration ChiCTR-ECS-14005052, http://www.chictr.org
 , Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China)

/pdf/the-nine-year-changes-of-the-incidence-and-characteristics-1h7sh16eyk.pdf

The nine-year changes of the incidence and characteristics of metabolic syndrome in China: longitudinal comparisons of the two cross-sectional surveys in a newly formed urban community

During the multistage fracturing of shale gas horizontal wells, casing damage frequently occurs, making it essential to evaluate casing stress and deformation. This paper establishes a mathematical model of thermo-hydro-mechanical coupling and a finite element model of casing-cement sheath-formation (CCF). This paper examines the effects of temperature, casing thickness, nonuniform in situ stress, mechanical properties of cement sheath, and treating pressure on the stress and deformation of CCF. Finally, the study investigates the variation of local in situ stress at the heel and casing stress from toe to heel. The results show that the low temperature of CCF, high elastic modulus of cement sheath, small casing thickness, high treating pressure, and large nonuniform in situ stress can exacerbate casing stress. After pumping off, the local in situ stress and its nonuniformity near heel gradually increased, and the effective stress of casing increases compared with the pumping on the process. As the fracturing stages increase, the effective stress of casing at heel increases, and the casing at heel preferentially damages. The results provide a theoretical basis and guidance for maintaining wellbore integrity and preventing casing damage in the multistage fracturing of shale gas horizontal wells. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/ese3.1496

Analysis of casing stress during multistage fracturing of shale gas horizontal wells considering thermo‐hydro‐mechanical coupling

The invention discloses a casing pipe pressure control well cementation process, and belongs to the technical field of oil and gas development well cementation. The casing pressure control well cementation process sequentially comprises a casing running stage, a cement injection and displacement stage and a bump pressure and setting waiting stage. In the casing running stage, the cementing and displacing stage and the bumping and waiting stage, the well bottom circulation equivalent density of the narrow safety density window well section is kept between the pore pressure equivalent density and the rupture pressure equivalent density corresponding to the narrow safety density window well section by controlling the wellhead annulus pressure. In the well cementation process, the wellhead annulus pressure is controlled; the well bottom circulation equivalent density corresponding to the narrow safety density window well section is enabled to be between the pore pressure equivalent densityand the rupture pressure equivalent density; it is ensured that a weak pressure-bearing stratum is not pressed to leak while the oil and gas display layer is pressed stably, the casing well cementation construction risk of a narrow safety density window well section is reduced, the well cementation quality is improved, the well integrity is improved, and the development benefits are ensured.

A casing pipe pressure control well cementation process

Gaoshiti-Moxi structure belt of An-Yue Sinian gas reservoir, which was China’s largest monomer Marine carbonate gas reservoir up to now, located in vying-dragon female temple structure group that belong to the ancient uplift slope of the middle of Sichuan. With the exploration and development of high temperature and high pressure carbonate reservoir, a large number of challenges and problems, such as long isolation section, active oil-gas show, large temperature difference, prone to super retarding cement slurry and gas channeling at flare position, have been encountered in the cementing of 177.8 mm hang-liner. In order to solve these problems, numerous measures and methods have been put into use for reducing the safety risk of cementing and improving cementing quality. The large temperature difference channeling cement slurry system, effective anti-pollution spacer and high-pressure packer type liner hanger were developed and applied for field tests in the early stage of development. In addition, equilibrium pressure cementing technology, optimizing of centralizer placement and plasma column structure, improvement of pump displacement and hold pressure while waiting on cement were used to ensure nice displacement efficiency and cementing quality. As Moxi X well for example, the cementing quality factor of merit was 40.29% and the qualification rate was up to 78.87% after adopting the cementing measures and methods above. The cementing quality was much higher than previous level and provided technical support for Gaoshiti-Moxi area.

/pdf/challenges-and-methods-to-improve-well-cementing-quality-for-tfnpcumzvt.pdf

Challenges and Methods to Improve Well Cementing Quality for 177.8 mm Liner in Gaoshiti-Moxi Area

The invention discloses a drilling liner pressure control well cementation process, and belongs to the technical field of oil and gas development well cementation. The drilling liner pressure controlwell cementation process sequentially comprises a casing running stage, a drilling liner hanger seating and hanging stage, a cementing and replacing stage, a bump pressure and drill string pulling-outstage and a setting waiting stage. In the casing running stage, the drilling liner hanger seating and hanging stage, the cement injecting and replacing stage, the bump pressure and drill string pulling-out stage and the waiting stage, the well bottom circulation equivalent density of the narrow safety density window well section is kept between the pore pressure equivalent density and the rupturepressure equivalent density corresponding to the narrow safety density window well section by controlling the wellhead annulus pressure. According to the well cementation technology, through wellheadannulus pressure control, the well bottom circulation equivalent density corresponding to the narrow safety density window well section is made to be between the pore pressure equivalent density andthe rupture pressure equivalent density, it is guaranteed that a pressure-bearing weak stratum is not pressed to leak while the oil and gas display layer is pressed stably, the drilling liner well cementation construction risk is reduced, and the well cementation quality is improved.

A drilling liner pressure control well cementation process

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