Testosterone enhances whereas estrogen inhibits calcium oxalate stone formation in ethylene glycol treated rats

Relationship Between Serum Testosterone Levels and Kidney Stones Prevalence in Men

BACKGROUND

The role of serum testosterone levels in male renal stone formation remains controversial. This study aimed to evaluate the relationship between serum testosterone levels and kidney stone prevalence in males.

METHODS

We conducted a cross-sectional study based on the data from the National Health and Nutrition Examination Survey 2011-2016, which included 6,633 male participants, to investigate the association between testosterone levels and the prevalence of kidney stones.

RESULTS

In this study, using the highest quartile of serum testosterone as a reference, a logistic regression model adjusted for confounders in all participants showed that the first quartile (OR: 1.375, p = 0.016), the second quartile (OR: 1.348, p = 0.021), and the third quartile (OR: 1.472, p = 0.003) of testosterone significantly increased kidney stone risks. In the 41-60 age group, the ORs of kidney stone risk in the first, second, and third of serum testosterone were 1.904 (P = 0.005), 1.599 (P = 0.040), and 1.734 (P = 0.015), respectively. This trend can also be found in the 61-80-year group, except in the first quartile of serum testosterone (OR: 1.169, P = 0.436). Adjusted smoothed curves suggest a non-linear relationship between the 8 quantiles of serum testosterone and the risk of kidney stones in all participants and the 61-80 age group and a significant negative relationship in the 41-60 age group (OR: 0.921, P = 0.0193). But no correlation was seen in the 20-40 group.

CONCLUSIONS

Serum testosterone levels were significantly inversely associated with the prevalence of kidney stones in men over 40 years of age, but no correlation was seen in the 20-40 group. The role of testosterone in stone formation should be redefined, and its effect should be further verified.

Urolithiasis: Presentation and Surgical Outcome at a Tertiary Care Hospital in Ethiopia

Background

The prevalence of urolithiasis is on a rising trend in tropical and sub-Saharan African countries. The treatment options and data on the surgical outcome are limited in our country. This study was designed to assess the clinical presentation, surgical management and outcome of patients operated on for urolithiasis.

Patients and Materials

A retrospective study of all patients admitted and operated for urolithiasis at St. Paul’s hospital millennium medical college (SPHMMC) from July, 2016 to December, 2017 was conducted. Factors associated with surgical outcome were identified with binary logistic regression.

Results

Urolithiasis constituted 247 (30.0%) of 824 urologic admissions. Of these, 202 (Male:Female = 2:1) patients were investigated. The mean age was 37.1 ± 14.4 years (range, 10–85 years). The mean duration of illness was 16.7 ± 18.7 months and the commonest presenting symptom was isolated flank pain (97, 48.0%). A majority of the patients (186, 92.1%) had upper tract stones of which 96 (51.6%) were renal stones. More than two-thirds (164, 81.2%) of the patients had complications at presentation, and hydronephrosis (148, 73.3%) was the major one. Half of the patients (104, 51.5%) were treated with endoscopic procedures, 88 (43.6%) with open stone surgery and in 10 (4.9%) patients both were performed. Nephrectomy was done to 15 (7.4%) patients. Intraoperative and postoperative complications were noted in 16 (7.9%) and 26 (12.9%) patients, respectively. These complications were higher in patients with comorbid illness (AOR = 2.44; 95% CI 1.12–5.31; p = 0.024). Complete stone clearance was achieved in more than half of the clients (114, 61.0%). Multiple stones (AOR = 8.33; 95% CI 2.53–27.43; p < 0.0001) and endoscopic procedures (AOR = 4.17; 95% CI 1.57–10.71; p = 0.003) had significant association with incomplete stone clearance.

Conclusion

Patients’ presentation in this review was not different from studies elsewhere. Endoscopic procedures are emerging in our set up; however, it was significantly associated with incomplete stone clearance. Strategies to improve outcome (stone clearance) need to be implemented accordingly.

Animal Models for Studying Stone Disease

Animals have stone disease too. There are several animal models for the research of human stone disease. Rodents are the most frequently used for stone research, although they are not prone to forming crystals in the kidneys. Ethylene glycol (EG), sodium oxalate and l-hydroxyproline are common lithogenic agents. Dogs and pigs were also reported as a study animal for stone disease. However, the breeding costs and body size are too high. The most-used genetic study animal for stone disease was the mouse, but it was high-cost. Calcium oxalate (CaOx) crystals can also be light microscopically observed in the Malphigian tubules of Drosophila melanogaster, induced by adding EG to the food. Genetic studies of flies can be done by cross-breeding, and this has a lower cost than using mice. The fly model also has several advantages, including minimal breeding equipment, the fact that it is easier to reach larger numbers in a short time with flies, that crystals can be observed under microscopy, and that they allow genetic study. We suggest the fly will be an ideal animal model for stone research in the future.

Nephrolithiasis and Polycystic Ovary Syndrome: A Case-Control Study Evaluating Testosterone and Urinary Stone Metabolic Panels

Introduction

Both elevated testosterone and polycystic ovary syndrome (PCOS) have been speculated as possible risk factors for kidney stone formation; however, the details of this potential relationship with regards to 24-hour urine metabolic panels and stone composition have not previously been characterized.

Methods

A total of 74 PCOS patients were retrospectively identified and matched with a cohort of female stone formers at a 3 : 1 ratio (by age and BMI). All patients had 24-hour urinary metabolic panels and stone compositions. These groups were compared using Pearson chi-square and Student t-tests. Additionally, the PCOS group was differentiated based on free testosterone using multivariate analysis.

Results

The case-control cohort showed that PCOS patients had significantly lower sodium excretion (p=0.015) and hypernatriuria rates (28.9% vs 50.9%, p=0.009). The PCOS-testosterone cohort demonstrated that high testosterone patients had significantly higher citrate values (p=0.041) and significantly lower odds of hypocitraturia (36.7% vs 54.2%, OR = 0.2, p=0.042). The high testosterone group also had higher sodium excretion (p=0.058) with significantly higher odds of having hypernatriuria (40.0% vs 13.6%, OR = 13.3, p=0.021). No significant patterns were revealed based on stone composition analysis.

Conclusions

Compared to healthy stone formers, PCOS patients did not demonstrate significant differences in 24-hour urine and stone composition values. Elevated free testosterone in PCOS patients has a significant association with higher urinary citrate and sodium values: findings that in and of themselves do not confirm the hypothesized increased risk of stone formation. This patient cohort may provide deeper insight into the interplay between androgens and stone formation; however, further study is needed to fully characterize the possible relationship between PCOS and stone formation.

Relation of urinary stone disease with androgenetic alopecia and serum testosterone levels

We aimed to investigate the relationship among urinary stone disease, androgenetic alopecia (AGA), and serum testosterone (T) levels. Between January 2008 and November 2015, we retrospectively investigated the biochemical parameters and anthropometric characteristics (height and weight) of 200 patients who had urinary tract stones. For the control group, we selected at random 168 participants who had no history of urolithiasis. Demographic data, such as participants' age, body mass index (BMI), hypertension (HT), diabetes mellitus (DM), baldness pattern, and serum T level were recorded. All participants were male, over 18 and under 60 years of age. We determined that risk of urolithiasis increased 1.3-fold in patients with vertex pattern alopecia and 2.1-fold in patients with total alopecia compared with those with no hair loss. In the severe balding Groups (Group III and Group IV), presence of testosterone deficiency was more frequent in patients with urinary stone disease (P = 0.041, OR = 2.38). Although in the non- balding and mild balding Groups (Group I and Group II), presence of testosterone deficiency was also more frequent in patients with urinary stone disease, a statistically significant difference was not seen. Significantly, we found that the presence of testosterone deficiency was more frequent in patients with urinary stone disease and who had severe AGA.

In female rats, ethylene glycol treatment elevates protein expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) without inducing hyperoxaluria

Aim

To investigate whether the sex-dependent expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) changes in a rat model of ethylene glycol (EG)-induced hyperoxaluria.

Methods

Rats were given tap water (12 males and 12 females; controls) or EG (12 males and 12 females; 0.75% v/v in tap water) for one month. Oxaluric state was confirmed by biochemical parameters in blood plasma, urine, and tissues. Expression of sat-1 and rate-limiting enzymes of oxalate synthesis, alcohol dehydrogenase 1 (Adh1) and hydroxy-acid oxidase 1 (Hao1), was determined by immunocytochemistry (protein) and/or real time reverse transcription polymerase chain reaction (mRNA).

Results

EG-treated males had significantly higher (in μmol/L; mean ± standard deviation) plasma (59.7 ± 27.2 vs 12.9 ± 4.1, P < 0.001) and urine (3716 ± 1726 vs 241 ± 204, P < 0.001) oxalate levels, and more abundant oxalate crystaluria than controls, while the liver and kidney sat-1 protein and mRNA expression did not differ significantly between these groups. EG-treated females, in comparison with controls had significantly higher (in μmol/L) serum oxalate levels (18.8 ± 2.9 vs 11.6 ± 4.9, P < 0.001), unchanged urine oxalate levels, low oxalate crystaluria, and significantly higher expression (in relative fluorescence units) of the liver (1.59 ± 0.61 vs 0.56 ± 0.39, P = 0.006) and kidney (1.77 ± 0.42 vs 0.69 ± 0.27, P < 0.001) sat-1 protein, but not mRNA. The mRNA expression of Adh1 was female-dominant and that of Hao1 male-dominant, but both were unaffected by EG treatment.

Conclusions

An increased expression of hepatic and renal oxalate transporting protein sat-1 in EG-treated female rats could protect from hyperoxaluria and oxalate urolithiasis.

Sex Steroid Hormone Levels May Not Explain Gender Differences in Development of Nephrolithiasis

OBJECTIVES

To determine whether serum sex steroid hormone levels, or the subsequent change in those levels over time, represent a risk factor for the development of nephrolithiasis in men.

METHODS

We retrospectively identified patients participating in a long-term cohort study (Rochester Epidemiology Project) in Olmsted County, Minnesota. Patients had previously undergone baseline detailed clinical examination and sex steroid hormone studies, including estradiol, testosterone, and bioavailable testosterone. Patients were followed on a biennial basis. Records were then reviewed to assess for formation of nephrolithiasis.

RESULTS

We identified 684 patients, with a median follow-up for stone formation of 12.8 years. All 684 patients had measurement of testosterone, of which 78.9% were in normal range. Five hundred eighteen men had baseline-free testosterone, of whom 88.6% were normal. Three hundred seventy-one patients had baseline estradiol, of whom 88.7% were normal. One hundred two men (14.9%) were found to have stones, with 61 of those (59.8%) occurring before first hormone measurement and 41 (40.2%) occurring after. On multivariate analysis, there was no significant association of serum hormones with nephrolithiasis, although a trend toward higher baseline testosterone and stones was seen (odds ratio [OR] 1.29; 95% confidence intervals [CI] 0.71, 2.33). Using a time-to-event for incident stone formation, we found no significant association of baseline hormones or percentage change in hormone levels over time with risk of stones.

CONCLUSION

We found no significant association of sex steroid hormone levels with the risk of nephrolithiasis formation in men, although a weak trend toward an increased risk with elevated testosterone was seen.

Serum estradiol and testosterone levels in kidney stones disease with and without calcium oxalate components in naturally postmenopausal women

Objective

Epidemiological data reveal that the overall risk for kidney stones disease is lower for women compared to age-matched men. However, the beneficial effect for the female sex is lost upon menopause, a time corresponding to the onset of fall in estrogen levels. The aim of this study was to describe the serum estradiol (E2) and testosterone (T) characteristics of naturally postmenopausal women with kidney stones.

Methods

113 naturally postmenopausal women with newly diagnosed kidney stones (aged 57.4±4.98 years) and 84 age frequency matched stone-free controls (56.9±4.56 years) were validly recruited in the case-control study. The odds ratios (ORs) for the associations between sex hormones and kidney stones were estimated with logistic regression models, adjusting for demographic data and medical history. Patients were also stratified analyzed according to stone components (calcium oxalate stones [COS]; non-calcium oxalate stones [NCOS]).

Results

Serum E2 (21.1 vs. 31.1 pg/ml) was significantly lower in kidney stones patients compared to controls. Post-hoc analysis demonstrated that this effect was driven by COS patients (p<0.001). According to tertiles of the E2 levels, a significant higher frequency of COS was seen in the lowest E2 group (p <0.001). Multiple logistic regression analysis identified E2 level as a strong factor that was independently associated with the risk for COS (per 1 SD increase, OR=0.951, 95% confidence interval [CI] = 0.919-0.985; highest: lowest tertile, OR=0.214, 95%CI = 0.069-0.665). However, serum T levels did not significantly differ among the groups.

Conclusions

Naturally postmenopausal women with higher remaining estradiol levels appear less likely to suffer from kidney calcium oxalate stones. However, no correlation was found between serum T level and kidney stones. These findings support the hypothesis that higher postmenopausal endogenous estrogens may protect against kidney stones with ageing.

Is polycystic ovarian syndrome a risk factor for urolithiasis?

Urinary stone disease is a complex multifactorial disorder influenced by both intrinsic and environmental factors. It is generally known that age and sex are risk factors for urinary stone disease. Also men have higher mean urinary oxalate concentrations than women. In addition, in animal and human studies, testosterone has been shown to increase the formation of urinary stones. This suggests that sex hormones are considered to be involved in the pathogenesis of stone disease. Polycystic ovary syndrome (PCOS) is one of the most frequent endocrine disorders of women in the reproductive age, affecting 5-10 % of women in this life span. It is characterized with chronic anovulation\oligo-ovulation, clinical or biochemical evidence of hyperandrogenism and polycystic ovaries on ultrasound examination. Hyperandrogenism, the main feature of PCOS, may trigger the urinary stone formation besides hirsutism, alopecia and acne. Therefore, we hypothesize that PCOS accompanied by hyperandrogenism may be a risk factor in the formation of urinary stone disease.