Heavy Metals and Trajectories of Anti-Müllerian Hormone During the Menopausal Transition.

BACKGROUND: Experimental and epidemiological studies have linked metals with women's reproductive aging, but the mechanisms are not well understood. Disrupted ovarian folliculogenesis and diminished ovarian reserve could be a pathway through which metals impact reproductive hormones and outcomes. OBJECTIVE: The study aimed to evaluate the associations of heavy metals with anti-Müllerian hormone (AMH), a marker of ovarian reserve. METHODS: The study included 549 women from the Study of Women's Health Across the Nation with 2252 repeated AMH measurements from 10 to 0 years before the final menstrual period (FMP). Serum AMH concentrations were measured using picoAMH ELISA. Urinary concentrations of arsenic, cadmium, mercury, and lead were measured using high-resolution inductively coupled plasma mass spectrometry. Multivariable linear mixed regressions modeled AMH as a function of time before the FMP interaction terms between metals and time to the FMP were also included. RESULTS: Adjusting for confounders, compared with those in the lowest tertile, women in the highest tertile of urinary arsenic or mercury concentrations had lower AMH concentrations at the FMP (percent change: -32.1%; 95% CI, -52.9 to -2.2, P-trend = .03 for arsenic; percent change: -40.7%; 95% CI, -58.9 to -14.5, P-trend = .005 for mercury). Higher cadmium and mercury were also associated with accelerated rates of decline in AMH over time (percent change per year: -9.0%; 95% CI, -15.5 to -1.9, P-trend = .01 for cadmium; -7.3%; 95% CI, -14.0 to -0.1, P-trend = .04 for mercury). CONCLUSION: Heavy metals including arsenic, cadmium, and mercury may act as ovarian toxicants by diminishing ovarian reserve in women approaching the FMP.

Biological variation of serum thyrotropin and thyroid hormones concentrations determined at 8-week intervals for 1 year in clinically healthy cats.

BACKGROUND: Cats commonly develop thyroid disease but little is known about the long-term biological variability of serum thyroid hormone and thyrotropin (thyroid-stimulating hormone; TSH) concentrations. OBJECTIVES: We aimed to determine the long-term biological variation of thyroid hormones and TSH in clinically healthy cats. METHODS: A prospective, observational study was carried out. Serum samples for analysis of total thyroxine (T4, by radioimmunoassay [RIA] and homogenous enzyme immunoassay [EIA]), triiodothyronine (T3 ), free T4 (by dialysis), and TSH were obtained every 8 weeks for 1 year from 15 healthy cats, then frozen until single-batch analysis. Coefficients of variation (CV) within individual cats ( CV I ) and among individual cats ( CV G ), as well as the variation between duplicates (ie, analytical variation [ CV A ]) were determined with restricted maximum likelihood estimation. The indices of individuality (IoI) and reference change values (RCVs) for each hormone were calculated. RESULTS: Some thyroid hormones showed similar (total T4 by EIA) or greater (TSH) interindividual relative to intraindividual variation resulting in intermediate to high IoI, consistent with previous studies evaluating the biological variation of these hormones weekly for 5-6 weeks. By contrast, total T4 (by RIA) and free T4 had a low IoI. Total T3 had a high ratio of CV A to CV I ; therefore, interindividual variation could not be distinguished from analytical variation. No seasonal variability in the hormones could be demonstrated. CONCLUSIONS: Clinicians might improve the diagnosis of feline thyroid disease by establishing baseline concentrations for analytes with intermediate-high IoI (total T4, TSH) for individual cats and applying RCVs to subsequent measurements.

Associations Between Repeated Measures of Urinary Phthalate Metabolites With Hormones and Timing of Natural Menopause.

Phthalates, ubiquitous endocrine-disrupting chemicals, may affect ovarian folliculogenesis and steroidogenesis. We examined the associations of urinary phthalate metabolites with hormones including estradiol, testosterone, follicle-stimulating hormone (FSH), sex hormone-binding globulin (SHBG), and anti-Müllerian hormone (AMH), and timing of natural menopause in midlife women. Data were from 1189 multiracial/multiethnic women aged 45 to 56 years without hormone therapy from the Study of Women's Health Across the Nation (SWAN). Urinary concentrations of 12 phthalate metabolites and hormones were repeatedly measured in 1999 to 2000 and 2002 to 2003, resulting in a total of 2111 observations. Linear mixed-effect models were used to calculate percentage differences (%D) and 95% CIs in serum concentrations of estradiol, testosterone, FSH, SHBG, and AMH. Cox proportional-hazards models were used to calculate hazard ratios (HRs) and 95% CIs of natural menopause. We observed statistically significant associations of phthalate metabolites with lower testosterone concentrations: MCOP with testosterone (%D: -2.08%; 95% CI, -3.66 to -0.47) and MnBP with testosterone (%D: -1.99%; 95% CI, -3.82 to -0.13), after adjusting for multiple comparisons with false discovery rates less than 5%. Lower AMH concentrations were also found with higher MECPP (%D: -14.26%; 95% CI, -24.10 to -3.14), MEHHP (%D: -15.58%; 95% CI, -24.59 to -5.50), and MEOHP (%D: -13.50%; 95% CI, -22.93 to -2.90). No associations were observed for other hormones or timing of natural menopause. These results suggest that exposure to phthalates may affect circulating levels of testosterone and diminish the ovarian reserve in midlife women. Given the widespread exposure, reduced exposure to phthalates may be a key step to prevent reproductive effects of phthalates.

Exposure to heavy metals and hormone levels in midlife women: The Study of Women's Health Across the Nation (SWAN).

Exposure to heavy metals may alter the circulating levels of sex hormones. However, epidemiologic studies on heavy metals and sex hormones have been limited, and results have been inconsistent. We assessed the associations of heavy metals assayed in urine, including arsenic, cadmium, lead, and mercury, with repeated measures of serum estradiol (E2), follicle-stimulating hormone (FSH), testosterone, and sex hormone-binding globulin (SHBG) levels in the Study of Women's Health Across the Nation Multi-Pollutant Study. The sample included 1355 White, Black, Chinese, and Japanese women, aged 45-56 years at baseline (1999-2000), whose serum hormone levels were repeatedly measured through 2017. Urinary metal concentrations were measured at baseline. Linear mixed effect models were used to calculate percent changes in serum hormone levels per doubling of urinary metal concentrations, adjusting for demographics, socioeconomic status, lifestyle, health-related factors, and urinary creatinine. After multivariable adjustment, a doubling of urinary metal concentration was associated with lower E2 levels by 2.2% (95% CI: 4.0%, -0.3%) for mercury and 3.6% (95% CI: 5.7%, -1.6%) for lead; higher FSH levels by 3.4% (95% CI: 0.9%, 5.9%) for lead; and higher SHBG levels by 3.6% (95% CI: 1.3%, 5.9%) for cadmium. The overall joint effect using the Bayesian kernel machine regression showed that metal mixtures were inversely associated with E2 and positively associated with FSH levels. No association was found between metals and testosterone levels. Results from this prospective cohort study demonstrate that environmental heavy metal exposures, including cadmium, mercury, and lead, may disturb circulating levels of E2, FSH, and SHBG in midlife women.

Biological variation of biochemical analytes determined at 8-week intervals for 1 year in clinically healthy cats.

BACKGROUND: Biological variation helps determine whether population-based or subject-based reference intervals are more appropriate to assess changes in serial analytical values. Previous studies have investigated the biological variation of biochemical analytes weekly or with variable frequency over 5-14 weeks in cats, but none have considered biological variation at less frequent intervals over 1 year. OBJECTIVES: We aimed to evaluate the long-term biological variation of 19 biochemical analytes in clinically healthy cats. METHODS: A prospective, observational study in which 15 clinically healthy, client-owned cats were sampled for serum biochemical analyses every 8 weeks for 1 year. Frozen serum samples were single-batch analyzed. Restricted maximum likelihood estimation was used to determine the coefficients of variation (CV), describing variation within each cat, between cats, and the analytical variation. These CVs were used to determine the indices of individuality and reference change values (RCVs). RESULTS: Albumin, alkaline phosphatase, creatine kinase, and globulin had high indices of individuality, indicating that they are best evaluated by RCVs. Phosphorus, potassium, chloride, sodium, symmetric dimethylarginine, and total CO2 had low indices of individuality, indicating that population-based reference intervals are appropriate. Alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, calcium, cholesterol, creatinine, glucose, total bilirubin, and total protein had intermediate indices of individuality, indicating that RCVs may provide additional insight into the interpretation of analyte measurements beyond the population-based reference intervals. CONCLUSIONS: For many analytes, the biological variation detected was similar to that reported in prior studies. Clinicians should consider the biological variation of analytes to best interpret clinically relevant changes in serial analyte measurements.

Perfluoroalkyl Substances and Incident Natural Menopause in Midlife Women: The Mediating Role of Sex Hormones.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) have been associated with earlier natural menopause; however, the underlying mechanisms are not well understood, particularly the extent to which this relationship is mediated by sex hormones. We analyzed data (1999-2017) on 1,120 premenopausal women from the Study of Women's Health Across the Nation (SWAN). Causal mediation analysis was applied to quantify the degree to which follicle-stimulating hormone (FSH) and estradiol levels could mediate the associations between PFAS and incident natural menopause. Participants with higher PFAS concentrations had shorter times to natural menopause, with a relative survival of 0.82 (95% confidence interval (CI): 0.69, 0.96) for linear perfluorooctane sulfonate (n-PFOS), 0.84 (95% CI: 0.69, 1.00) for sum of branched-chain perfluorooctane sulfonate (Sm-PFOS), 0.79 (95% CI: 0.66, 0.93) for linear-chain perfluorooctanoate (n-PFOA), and 0.84 (95% CI: 0.71, 0.97) for perfluorononanoate (PFNA), comparing the highest tertile of PFAS concentrations with the lowest. The proportion of the effect mediated through FSH was 8.5% (95% CI: -11.7, 24.0) for n-PFOS, 13.2% (95% CI: 0.0, 24.5) for Sm-PFOS, 26.9% (95% CI: 15.6, 38.4) for n-PFOA, and 21.7% (6.8, 37.0) for PFNA. No significant mediation by estradiol was observed. The effect of PFAS on natural menopause may be partially explained by variations in FSH concentrations.

Cellular heterogeneity of human fallopian tubes in normal and hydrosalpinx disease states identified using scRNA-seq.

Fallopian tube (FT) homeostasis requires dynamic regulation of heterogeneous cell populations and is disrupted in infertility and ovarian cancer. Here, we applied single-cell RNA-seq to profile 59,738 FT cells from four healthy, pre-menopausal subjects. The resulting cell atlas contains 12 major cell types representing epithelial, stromal, and immune compartments. Re-clustering of epithelial cells identified four ciliated and six non-ciliated secretory epithelial subtypes, two of which represent potential progenitor pools: one leading to mature secretory cells and the other contributing to either ciliated cells or one of the stromal cell types. To understand how FT cell numbers and states change in a disease state, we analyzed 17,798 cells from two hydrosalpinx samples and observed shifts in epithelial and stromal populations and cell-type-specific changes in extracellular matrix and TGF-ß signaling; this underscores fibrosis pathophysiology. This resource is expected to facilitate future studies aimed at expanding understanding of fallopian tube homeostasis in normal development and disease.

Bacterial culture and immunohistochemical detection of bacteria and endotoxin in cats with suppurative cholangitis-cholangiohepatitis syndrome.

OBJECTIVE: To characterize the frequency and type of bacterial infection by culture- and immunohistochemical (IHC)-based methods and determine the impact of infection on clinical features and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome (S-CCHS). ANIMALS: 168 client-owned cats with S-CCHS (cases). PROCEDURES: Clinical features, bacterial culture results, culture-inoculate sources, and survival details were recorded. Cases were subcategorized by comorbidity (extrahepatic bile duct obstruction, cholelithiasis, cholecystitis, ductal plate malformation, biopsy-confirmed inflammatory bowel disease, and biopsy-confirmed pancreatitis) or treatment by cholecystectomy or cholecystoenterostomy. Culture results, bacterial isolates, Gram-stain characteristics, and IHC staining were compared among comorbidities. Lipoteichoic acid IHC staining detected gram-positive bacterial cell wall components, and toll-like receptor expression IHC reflected pathologic endotoxin (gram-negative bacteria) exposure. RESULTS: Clinical features were similar among cases except for more frequent abdominal pain and lethargy in cats with positive culture results and pyrexia, abdominal pain, and hepatomegaly for cats with polymicrobial infections. Bacteria were cultured in 93 of 135 (69%) cats, with common isolates including Enterococcus spp and Escherichia coli. IHC staining was positive in 142 of 151 (94%) cats (lipoteichoic acid, 107/142 [75%]; toll-like receptor 4, 99/142 [70%]). With in-parallel interpretation of culture and IHC-based bacterial detection, 154 of 166 (93%) cats had bacterial infections (gram-positive, 118/154 [77%]; gram-negative, 111/154 [72%]; polymicrobial, 79/154 [51%]). Greater frequency of bacterial isolation occurred with combined tissue, bile, and crushed cholelith inoculates. Infection and gram-positive bacterial isolates were associated with significantly shorter long-term survival times. CLINICAL RELEVANCE: S-CCHS was associated with bacterial infection, pathologic endotoxin exposure, and frequent polymicrobial infection in cats. Combined tissue inoculates improved culture detection of associated bacteria.

Clinical features, concurrent disorders, and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome.

OBJECTIVE: To characterize clinical features, comorbidities, frequency of bacterial isolation, and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome (S-CCHS). ANIMALS: 168 client-owned cats with S-CCHS. PROCEDURES: Data were prospectively (1980 to 2019) collected regarding clinical features, comorbidities, bacterial infection, illness duration, and treatments. Variables were evaluated for associations with survival time. RESULTS: Median age of cats was 10.0 years, with no breed or sex predilection observed. Common clinical features included hyporexia (82%), hyperbilirubinemia (80%), lethargy (80%), vomiting (80%), jaundice (67%), weight loss (54%), and hypoalbuminemia (50%). Comorbidities included extrahepatic bile duct obstruction (53%), cholelithiasis (42%), cholecystitis (40%), and ductal plate malformation (44%) as well as biopsy-confirmed inflammatory bowel disease (60/68 [88%]) and pancreatitis (41/44 [93%]). Bacterial cultures were commonly positive (69%) despite prebiopsy antimicrobial administration in most cats. Of surgically confirmed choleliths, diagnostic imaging identified only 58%. Among 55 cats with "idiopathic pancreatitis," 28 (51%) were documented to have transiting choleliths, and 20 had pancreatic biopsies confirming pancreatitis. Cholelithiasis (with or without bile duct obstruction) and cholecystectomy were associated with survival advantages. Survival disadvantages were found for leukocytosis, ≥ 2-fold increased alkaline phosphatase, and hyperbilirubinemia. Cholecystoenterostomy had no survival impact. Cats with ductal plate malformations were significantly younger at diagnosis and death than other cats. Chronic treatments with antimicrobials, S-adenosylmethionine, and ursodeoxycholic acid were common postbiopsy. CLINICAL RELEVANCE: S-CCHS in cats was associated with bacterial infection and various comorbidities and may be confused with pancreatitis. Surgically correctable morbidities (ie, cholecystitis, cholecystocholelithiasis) and cholecystectomy provided a significant survival advantage.

Patient Preferences for Receiving Gender-Affirming Hormone Therapy.

Purpose: To characterize patient preferences regarding gender-affirming hormone therapy (HT) providers and telemedicine use. Methods: Between May and October 2019, a survey was administered to adult patients attending a tertiary medical center's HT clinic. The survey included questions on demographics, barriers to care, and preferences for HT follow-up care. Interest in telemedicine was measured using a Likert scale. Multivariable logistic regression was used to identify patient factors associated with interest in telemedicine. Results: Among 111 patients, 63.1% (n=70) preferred an in-person visit with a specialist and 21.6% (n=24) preferred a video visit with their specialist. While only 15.3% (n=17) preferred follow-up with a primary care provider (PCP), 71.0% (n=80) felt comfortable transitioning future care to a PCP. Notably, 52.3% (n=58) of patients were interested in a telemedicine visit. Factors associated with interest in telemedicine included identifying as a transgender man (aOR 3.94, 95% CI [1.24-12.53], p=0.02), minority race/ethnicity (aOR 6.71, 95% CI [1.79-25.17], p=0.005), no need to travel (aOR 3.34, 95% CI [1.14-9.85], p=0.03), no concerns about video visits (aOR 14.66, 95% CI [4.34-49.56], p<0.0001), and concern about their PCP offering a broad range of gender services (aOR 8.63, 95% CI [2.41-29.67], p=0.0006). Conclusions: Patients presenting for HT follow-up prefer continued care with a specialist. However, patients were willing to transition care to PCPs and were interested in telemedicine before the COVID-19 pandemic.

Relationships between congenital peritoneopericardial diaphragmatic hernia or congenital central diaphragmatic hernia and ductal plate malformations in dogs and cats.

OBJECTIVE: To characterize the association between peritoneopericardial diaphragmatic hernia (PPDH) or congenital central diaphragmatic hernia (CCDH) and ductal plate malformations (DPMs) in dogs and cats. ANIMALS: 18 dogs and 18 cats with PPDH or CCDH and 19 dogs and 18 cats without PPDH or CCDH. PROCEDURES: Evaluation of clinical details verified PPDH or CCDH and survival times. Histologic features of nonherniated liver samples were used to categorize DPM. Immunohistochemical staining for cytokeratin-19 distinguished bile duct profiles per portal tract and for Ki-67-assessed cholangiocyte proliferation. Histologic features of herniated liver samples from PPDH or CCDH were compared with those of pathological controls (traumatic diaphragmatic hernia, n = 6; liver lobe torsion, 6; ischemic hepatopathy, 2). RESULTS: DPM occurred in 13 of 18 dogs with the proliferative-like phenotype predominating and in 15 of 18 cats with evenly distributed proliferative-like and Caroli phenotypes. Congenital hepatic fibrosis DPM was noted in 3 dogs and 2 cats and renal DPM in 3 dogs and 3 cats. No signalment, clinical signs, or clinicopathologic features discriminated DPM. Kaplan Meier survival curves were similar in dogs and cats. Bile duct profiles per portal tract in dogs (median, 5.0; range, 1.4 to 100.8) and cats (6.6; 1.9 to 11.0) with congenital diaphragmatic hernias significantly exceeded those in healthy dogs (1.4; 1.2 to 1.6) and cats (2.3; 1.7 to 2.6). Animals with DPM lacked active cholangiocyte proliferation. Histologic features characterizing malformative bile duct profiles yet without biliary proliferation were preserved in herniated liver lobes in animals with DPM. CONCLUSIONS AND CLINICAL RELEVANCE: DPM was strongly associated with PPDH and CCDH. Because DPM can impact health, awareness of its coexistence with PPDH or CCDH should prompt biopsy of nonherniated liver tissue during surgical correction of PPDH and CCDH.

Urinary metals and metal mixtures and timing of natural menopause in midlife women: The Study of Women's Health Across the Nation.

BACKGROUND: Exposure to metals and metal mixtures may influence ovarian aging. However, epidemiologic evidence of their potential impact is lacking. OBJECTIVE: We prospectively examined the associations of 15 urinary metal concentrations and their mixtures with natural menopause in the Study of Women's Health Across the Nation Multi-Pollutant Study. METHODS: The study population consisted of 1082 premenopausal women from multiple racial/ethnic groups, aged 45-56 years at baseline (1999-2000), with the median follow-up of 4.1 years. Urinary concentrations of 15 metals, including arsenic, barium, cadmium, cobalt, cesium, copper, mercury, manganese, molybdenum, nickel, lead, antimony, tin, thallium, and zinc, were measured at baseline. Natural menopause was defined as the final bleeding episode prior to at least 12 months of amenorrhea, not due to surgery or hormone therapy. Cox proportional hazards models were used to examine associations between individual metal concentrations and timing of natural menopause. The associations between metal mixtures and natural menopause were evaluated using elastic net penalized Cox regression, and an environmental risk score (ERS) was computed to represent individual risks of natural menopause related to metal mixtures. RESULTS: The median age at natural menopause was 53.2 years. Using the Cox proportional hazards models, the adjusted hazard ratio (HR) (and its 95% confidence interval (CI)) for natural menopause was 1.32 (1.03, 1.67) for arsenic and 1.36 (1.05, 1.76) for lead, comparing the highest with the lowest quartiles of metal concentrations. The predicted ages at natural menopause in the highest and lowest quartiles were 52.7 and 53.5 years for arsenic; and 52.9 and 53.8 years for lead. A significant association between ERS and menopause was also observed. Women in the highest vs. the lowest quartiles of ERS had an HR of 1.71 (1.36, 2.15), equivalent to a 1.6 year earlier median time to natural menopause. CONCLUSION: This study suggests that arsenic, lead, and metal mixtures are associated with earlier natural menopause, a risk factor for adverse health outcomes in later life.

Per- and Polyfluoroalkyl Substances and Hormone Levels During the Menopausal Transition.

CONTEXT: Per- and polyfluoroalkyl substances (PFAS) are widespread chemicals that may affect sex hormones and accelerate reproductive aging in midlife women. OBJECTIVE: To examine associations between serum PFAS concentrations at baseline (1999-2000) and longitudinal serum concentrations of follicle-stimulating hormone (FSH), estradiol, testosterone, and sex hormone-binding globulin (SHBG) at baseline and through 2015-2016. DESIGN: Prospective cohort. SETTING: General community. PARTICIPANTS: 1371 midlife women 45 to 56 years of age at baseline in the Study of Women's Health Across the Nation (SWAN). MAIN OUTCOME MEASURE(S): FSH, estradiol, testosterone, SHBG. RESULTS: In linear mixed models fitted with log-transformed hormones and log-transformed PFAS adjusting for age, site, race/ethnicity, smoking status, menopausal status, parity, and body mass index, FSH was positively associated with linear perfluorooctanoate [n-PFOA; 3.12% (95% CI 0.37%, 5.95%) increase for a doubling in serum concentration), linear perfluorooctane sulfonate [PFOS; 2.88% (0.21%, 5.63%)], branched perfluorooctane sulfonate [2.25% (0.02%, 4.54%)], total PFOS (3.03% (0.37%, 5.76%)), and 2-(N-ethyl-perfluorooctane sulfonamido) acetate [EtFOSAA; 1.70% (0.01%, 3.42%)]. Estradiol was inversely associated with perfluorononanoate [PFNA; -2.47% (-4.82%, -0.05%)) and n-PFOA (-2.43% (-4.97%, 0.18%)]. Significant linear trends were observed in the associations between PFOS and EtFOSAA with SHBG across parity (Ps trend ≤ 0.01), with generally inverse associations among nulliparous women but positive associations among women with 3+ births. No significant associations were observed between PFAS and testosterone. CONCLUSIONS: This study observed positive associations of PFOA and PFOS with FSH and inverse associations of PFNA and PFOA with estradiol in midlife women during the menopausal transition, consistent with findings that PFAS affect reproductive aging.

Disparities in hepatic copper concentrations determined by atomic absorption spectroscopy, inductively coupled plasma mass spectrometry, and digital image analysis of rhodanine-stained sections in dogs.

OBJECTIVE: To investigate disparities in hepatic copper concentrations determined by atomic absorption spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS), and digital image analysis of rhodanine-stained sections. ANIMALS: 516 dogs. PROCEDURES: Medical records of dogs for which hepatic biopsy specimens had been submitted between January 1999 and December 2019 for evaluation of copper content were reviewed. Paired hepatic copper concentrations obtained with digital image analysis and AAS or ICP-MS were compared, and Spearman rank correlation coefficients were calculated to test for correlations between qualitative copper accumulation scores and hepatic copper concentrations. For dogs for which ≥ 4 rhodanine-stained hepatic sections were available, intraindividual variation in copper distribution across hepatic sections was evaluated. RESULTS: Median hepatic copper concentrations obtained with digital image analysis exceeded concentrations obtained with AAS or ICP-MS. Concentrations were also higher in older dogs (≥ 9 years vs < 9 years), dogs of breeds with a typical body weight ≥ 20 kg (44 lb), and dogs with necroinflammatory changes or uneven copper distribution. Qualitative copper accumulation scores were significantly associated with hepatic copper concentrations; however, the correlation between qualitative score and concentration obtained with digital image analysis (rs = 0.94) was higher than the correlation between qualitative score and concentration obtained with AAS (rs = 0.75) or ICP-MS (rs = 0.57). The coefficient of variation for hepatic copper concentrations obtained with digital image analysis was significantly higher for dogs with higher hepatic copper concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that spectroscopic-spectrometric analysis of hepatic biopsy specimens commonly underestimated the concentration obtained by digital image analysis of rhodanine-stained sections.

Congenital erythropoietic protoporphyria and protoporphyric hepatopathy in a dog.

CASE DESCRIPTION: A 6-month-old sexually intact male Clumber Spaniel was evaluated because of small stature, recurrent dermatitis of the head, and progressive pigmentary hepatopathy. CLINICAL FINDINGS: Clinicopathologic findings included nonanemic hypochromic microcytosis, hypocholesterolemia, persistently high serum liver enzyme activities, and anicteric hyperbilirubinemia. Histologic examination of liver biopsy specimens collected when the dog was 6 months and 2 years of age revealed expansion and bridging of portal tracts, occasional centrilobular parenchymal collapse, scattered lymphoplasmacytic infiltrates, and dark red to brown pigment within large aggregates of macrophages, engorged bile canaliculi, and hepatocytes. The pigment failed to stain for the presence of iron, copper, bile, and glycoprotein and, when examined with polarized microscopy, emitted a yellow to green birefringence with occasional Maltese cross configurations. Further analyses confirmed marked porphyrin accumulation in blood, urine, feces, and liver tissue; protoporphyrin accumulation in RBCs and liver tissue; and a signature porphyrin profile and fluorescence peak consistent with erythropoietic protoporphyria. Advanced protoporphyric hepatopathy was diagnosed. The chronic dermatopathy was presumed to reflect protoporphyric photosensitivity. TREATMENT AND OUTCOME: Management was focused on avoiding conditions known to induce heme synthesis and catabolism, administrating ursodeoxycholic acid and antioxidants S-adenosylmethionine and vitamin E, and avoiding sunlight exposure. At follow-up at 4 years of age, the dog was stable without evidence of jaundice but with probable persistent erythropoietic protoporphyria-related solar dermatopathy. CLINICAL RELEVANCE: Clinical and histologic features of congenital erythropoietic protoporphyria and resultant protoporphyric hepatopathy, the diagnosis, and the successful management of a dog with these conditions over 4 years were described. Veterinarians should consider porphyric syndromes when unusual pigmentary hepatopathies are encountered.

Serum thyroxine and thyrotropin concentrations decrease with severity of nonthyroidal illness in cats and predict 30-day survival outcome.

BACKGROUND: In cats, nonthyroidal illness affects serum thyroid hormone concentrations. Serum thyroxine (T4 ) and triiodothyronine (T3 ) concentrations commonly decrease, whereas free T4 (fT4 ) concentrations vary unpredictably. Limited information exists regarding effects on serum thyrotropin (thyroid-stimulating hormone [TSH]) concentrations in cats with nonthyroidal illness syndrome (NTIS). OBJECTIVES: To characterize alterations in thyroid function that develop in cats with NTIS and to correlate these alterations with severity and outcome of the nonthyroidal illness. ANIMALS: Two hundred and twenty-two cats with NTIS and 380 clinically normal cats of similar age and sex. METHODS: Prospective, cross-sectional study. All cats had serum T4 , T3 , free T4 , and TSH concentrations measured. Cats were grouped based on illness severity and 30-day survival. RESULTS: Cats with NTIS had lower serum T4 and T3 concentrations than did normal cats (P < .001). Serum fT4 and TSH concentrations did not differ between groups. Serum T4 , T3 , and fT4 concentrations progressively decreased with increasing disease severity (P < .001). The 56 cats that died had lower T4 , T3 , and TSH concentrations than did the 166 survivors, with no difference in fT4 concentration. Multivariable logistic regression modeling indicated that serum T4 and TSH concentrations both predicted survival (P < .02). CONCLUSIONS AND CLINICAL IMPORTANCE: Cats with NTIS commonly develop low serum T4 , T3 , and TSH concentrations, the prevalence and extent of which increases with disease severity. Clinicians should consider evaluating thyroid function in cats with severe NTIS, because doing so could help determine probability of successful treatment responses before investing considerable time, effort, and finances in addressing the underlying disease.

Changes in kidney function during the menopausal transition: the Study of Women's Health Across the Nation (SWAN) - Michigan site.

OBJECTIVE: The aim of the study was to examine changes in kidney function during the menopausal transition (MT) and associations with levels of sex hormones (follicle stimulating hormone [FSH], sex hormone binding globulin [SHBG], estradiol, and testosterone). METHODS: We used data from the Michigan site of Study of the Women's Health Across the Nation, a longitudinal study of the MT. For this analysis, we included women who had at least one creatinine measure before the final menstrual period (FMP) and at least one creatinine measure after the FMP (n = 101 women with 440 observations). To determine whether the declines in estimated glomerular filtration rate (eGFR) remained constant during the MT, we used local weighted regression curves to fit eGFR estimates. We examined the association between sex hormones and eGFR with longitudinal mixed models adjusting for baseline age, day of menstrual cycle, and time from FMP. RESULTS: At baseline, women had a mean age of 45.4 ±â€Š2.5 years; 54% were African-American and 46% were white. Although eGFR declined significantly over time, declines were linear, consistent with declines in eGFR due to age alone rather than the MT. Total testosterone, estradiol, ratio of testosterone:estradiol, and free androgen index were not significantly associated with eGFR, whereas lower FSH (-0.039, 95% confidence interval [CI] -0.067 to -0.012) and higher SHBG (0.050, 95% CI 0.004-0.096) were associated with higher eGFR. CONCLUSIONS: Kidney function declines during the MT. Although associated with levels of FSH and SHBG, the rate of decline in eGFR is consistent with what would be expected of age alone.

Biologic variation of symmetric dimethylarginine and creatinine in clinically healthy cats.

BACKGROUND: Biologic variation of biochemical analytes, both within individuals and between individuals, determines whether population-based reference intervals (RIs) are appropriate when interpreting if a particular change is clinically relevant for a specific individual. OBJECTIVES: We aimed to evaluate the biologic variation of symmetric dimethylarginine (SDMA) in clinically healthy cats. METHODS: A prospective, observational study was performed in which 10 clinically healthy, client-owned cats were sampled for serum biochemical analyses once weekly for 6 weeks. Serum samples were frozen, and then single batches were analyzed for SDMA, using both liquid chromatography-mass spectroscopy (LC-MS), and an enzyme multiplied immunoassay technique (EMIT), and creatinine by modified Jaffe method. Restricted maximum likelihood estimations were used to determine the coefficients of variation (CVs) describing variation within each cat, between cats, and the analytical variation. These CVs were used to determine the indices of individuality and reference change values (RCVs). RESULTS: SDMA had an intermediate index of individuality that could be evaluated by both RCV and population-based RIs. In contrast, creatinine had a high index of individuality best evaluated with RCVs. Serum SDMA concentrations evaluated with either the reference standard, LC-MS, or the clinically used EMIT yielded similar results. CONCLUSIONS: Clinicians should consider biologic variation when selecting the best method for interpreting changes in biochemical analytes. Specifically, establishing each cat's baseline serum creatinine and SDMA concentrations during health, and applying RCVs to subsequent measurements could improve the recognition of meaningful biologic changes.

Associations of Perfluoroalkyl Substances with Incident Natural Menopause: The Study of Women's Health Across the Nation.

CONTEXT: Previous epidemiologic studies of per- and polyfluoroalkyl substances (PFASs) and menopausal timing conducted in cross-sectional settings were limited by reverse causation because PFAS serum concentrations increase after menopause. OBJECTIVES: To investigate associations between perfluoroalkyl substances and incident natural menopause. DESIGN AND SETTING: A prospective cohort of midlife women, the Study of Women's Health Across the Nation, 1999-2017. PARTICIPANTS: 1120 multiracial/ethnic premenopausal women aged 45-56 years. METHODS: Serum concentrations of perfluoroalkyls were quantified by high-performance liquid chromatography isotope dilution tandem mass spectrometry. Natural menopause was defined as the bleeding episode prior to at least 12 months of amenorrhea not due to surgery or hormone use. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Participants contributed 5466 person-years of follow-up, and 578 had incident natural menopause. Compared with the lowest tertile, women at the highest tertile of baseline serum concentrations had adjusted HR for natural menopause of 1.26 (95% CI: 1.02-1.57) for n-perfluorooctane sulfonic acid (n-PFOS) (Ptrend = .03), 1.27 (95% CI: 1.01-1.59) for branched-PFOS (Ptrend = .03), and 1.31 (95% CI: 1.04-1.65) for n-perfluorooctanoic acid (Ptrend = .01). Women were classified into four clusters based on their overall PFAS concentrations as mixtures: low, low-medium, medium-high, and high. Compared with the low cluster, the high cluster had a HR of 1.63 (95% CI: 1.08-2.45), which is equivalent to 2.0 years earlier median time to natural menopause. CONCLUSION: This study suggests that select PFAS serum concentrations are associated with earlier natural menopause, a risk factor for adverse health outcomes in later life.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) and their effects on the ovary.

BACKGROUND: Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are found widespread in drinking water, foods, food packaging materials and other consumer products. Several PFAS have been identified as endocrine-disrupting chemicals based on their ability to interfere with normal reproductive function and hormonal signalling. Experimental models and epidemiologic studies suggest that PFAS exposures target the ovary and represent major risks for women's health. OBJECTIVE AND RATIONALE: This review summarises human population and toxicological studies on the association between PFAS exposure and ovarian function. SEARCH METHODS: A comprehensive review was performed by searching PubMed. Search terms included an extensive list of PFAS and health terms ranging from general keywords (e.g. ovarian, reproductive, follicle, oocyte) to specific keywords (including menarche, menstrual cycle, menopause, primary ovarian insufficiency/premature ovarian failure, steroid hormones), based on the authors' knowledge of the topic and key terms. OUTCOMES: Clinical evidence demonstrates the presence of PFAS in follicular fluid and their ability to pass through the blood-follicle barrier. Although some studies found no evidence associating PFAS exposure with disruption in ovarian function, numerous epidemiologic studies, mostly with cross-sectional study designs, have identified associations of higher PFAS exposure with later menarche, irregular menstrual cycles, longer cycle length, earlier age of menopause and reduced levels of oestrogens and androgens. Adverse effects of PFAS on ovarian folliculogenesis and steroidogenesis have been confirmed in experimental models. Based on laboratory research findings, PFAS could diminish ovarian reserve and reduce endogenous hormone synthesis through activating peroxisome proliferator-activated receptors, disrupting gap junction intercellular communication between oocyte and granulosa cells, inducing thyroid hormone deficiency, antagonising ovarian enzyme activities involved in ovarian steroidogenesis or inhibiting kisspeptin signalling in the hypothalamus. WIDER IMPLICATIONS: The published literature supports associations between PFAS exposure and adverse reproductive outcomes; however, the evidence remains insufficient to infer a causal relationship between PFAS exposure and ovarian disorders. Thus, more research is warranted. PFAS are of significant concern because these chemicals are ubiquitous and persistent in the environment and in humans. Moreover, susceptible groups, such as foetuses and pregnant women, may be exposed to harmful combinations of chemicals that include PFAS. However, the role environmental exposures play in reproductive disorders has received little attention by the medical community. To better understand the potential risk of PFAS on human ovarian function, additional experimental studies using PFAS doses equivalent to the exposure levels found in the general human population and mixtures of compounds are required. Prospective investigations in human populations are also warranted to ensure the temporality of PFAS exposure and health endpoints and to minimise the possibility of reverse causality.