Gender and human chronic renal disease

Background: Gender affects the incidence, prevalence, and progression of renal disease. In animal models of the disease, female sex appears to modify the course of progression. Hormonal manipulation by male or female castration also changes the course of renal disease progression, suggesting direct effects of sex hormones in influencing the course of these maladies.Objective: This review examines the pertinent animal and human studies assessing the role of gender, and strives to shed light on the possible physiologic mechanisms underlying the effect of gender, on renal disease progression.Methods: A summary and evaluation of past and recent studies describing the rate of renal disease progression in animal models and humans as it pertains to gender is provided. In addition, studies elucidating the factors involved in the more modest renal progression rate in females are reviewed and conclusions drawn. Relevant English-language publications were identified by searching the PubMed database from January 1990 until November 2007 using the search terms gender, sex, renal disease, and kidney.Results: In polycystic kidney disease, membranous nephropathy, immunoglobulin A nephropathy, and “chronic renal disease of unknown etiology,” men progress at a faster rate to end-stage renal failure than do women. In type 1 diabetes mellitus, there is evidence that males are more likely to manifest signs of renal disease, such as proteinuria. The factors involved in this gender disparity may include diet, kidney and glomerular size, differences in glomerular hemodynamics, and the direct effects of sex hormones. In many, but not all, animal models of renal disease, estrogens slow progression rate. Several studies have recently evaluated the effect of selective estrogen receptor modulators on renal function in humans.Conclusion: Further studies assessing the factors involved in the gender disparity in renal disease progression and the effects of hormonal treatments are warranted.     

Age-related renal disease in female Dahl salt-sensitive rats is attenuated with 17²-estradiol supplementation by modulating nitric oxide synthase expression

Background: The incidence of chronic renal disease in women increases with aging, especially after menopause, suggesting that loss of sex hormones may contribute to the development and progression of renal disease. However, the mechanisms by which sex hormones, particularly estrogens, contribute to the disease process are unclear.Objective: The present study examined the effects of ovariectomy (OVX) with or without 17²-estradiol (E₂) supplementation (OVX+E₂) on the expression of inducible (iNOS) and endothelial (eNOS) nitric oxide synthase in the kidney.Methods: The study was performed in young (4 months [4M]) and aged (12 months [12M]) female Dahl salt-sensitive rats fed a low-sodium (0.1% NaCl) diet. At 3 months of age, the animals were either subjected to sham surgery, OVX, or OVX with implantation of an E₂ silastic pellet. The treatments were administered for either 1 or 9 months, rendering the animals 4 months of age or 12 months of age at the time of sacrifice, respectively. Renal expression of NOS isoforms was measured by Western blotting and immunohistochemistry.Results: OVX in the aged rats was associated with 35% and 25% decreases in medullary iNOS (mean [SEM] relative optical density [ROD]: 4M OVX, 1.81 [0.14] vs 12M OVX, 1.17 [0.16]; P < 0.05) and eNOS (mean ROD: 4M OVX, 1.91 [0.09] vs 12M OVX, 1.43 [0.15]; P < 0.05) protein expression, respectively, and a 25-fold increase in the abundance of CD68-positive cells, indicating macrophage infiltration (mean cells/mm²: 4M OVX, 1.18 [0.09] vs 12M OVX, 30.0 [0.74]; P < 0.001). E₂ supplementation either partially or completely attenuated these changes in iNOS (mean ROD: 4M OVX+E₂, 2.26 [0.08] vs 12M OVX+E₂, 1.70 [0.09]; P < 0.05), eNOS (mean ROD: 4M OVX+E₂, 2.03 [0.07] vs 12M OVX+E₂, 1.77 [0.11]; P = NS) and CD68 (mean cells/mm²: 4M OVX+E₂, 1.46 [0.07] vs 12M OVX+E₂, 6.87 [1.6]; P < 0.01) associated with OVX in the aging kidney.Conclusions: These data suggest that ovarian E₂ loss with aging may contribute to the development of age-related renal disease through downregulation of iNOS and eNOS protein abundance and increased renal inflammation in this animal model. Furthermore, E2 supplementation may be protective in the aging kidney by attenuating these changes.     

Association between testosterone, estradiol and sex hormone binding globulin levels in men with type 1 diabetes with nephropathy

Male sex is a risk factor for development and progression of diabetic nephropathy; however, the relationship between sex hormone levels and diabetic nephropathy in type 1 diabetic men is unknown. This was a prospective follow-up study as part of the nationwide Finnish Diabetic Nephropathy (FinnDiane) Study; 297 patients were followed for 5.9 ± 1.5 years. Serum total testosterone (Tt) and estradiol (Te), calculated free testosterone (cFt) and estradiol (cFe) and sex hormone binding globulin were measured at baseline and correlated with urinary albumin excretion rate, estimated glomerular filtration rate and markers of metabolic syndrome. Diabetes without renal disease was associated with decreased Tt (p < 0.001), Te (p < 0.001) and cFt (p = 0.001) levels compared with healthy non-diabetic men. With progression of renal disease from micro- to macroalbuminuria, this decrease in serum Tt was even more pronounced. Cox regression showed that cFt and cFe were independent predictors of the progression from macroalbuminuria to end-stage renal disease. Our study shows that men with type 1 diabetes exhibit dysregulated sex hormone levels, which is most pronounced in men with progressive renal disease, suggesting that sex hormones may play a role in the pathogenesis of diabetic nephropathy associated with type 1 diabetes.     

Clinicopathologic Features and Prognosis of Type 2 Diabetes Mellitus and Diabetic Nephropathy in Different Age Groups: More Attention to Younger Patients

Objective: Our study sought to investigate the clinicopathologic features and renal prognosis of patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN) in different age groups.Methods: A total of 315 patients with T2DM and biopsy-proven DN were enrolled and divided into three groups by age: the Youth group (≤44 years old), the Middle-aged group (45 to 59 years old), and the Elderly group (≥60 years old).Results: The Youth group, Middle-aged group, and Elderly group accounted for 19.05% (60/315), 59.37% (187/315), and 21.59% (68/315) of the patients in our study, respectively. The patients in the Youth group had a higher estimated glomerular filtration rate (calculated using the Chronic Kidney Disease–Epidemiology collaboration formula) (P<.001), a higher incidence of diabetic retinopathy (P = .044), and a higher incidence of being in the lower-risk chronic kidney disease heat map category (P = .046) but lower duration of diabetes (P = .016). Histologically, patients in the Youth group had the highest incidence of glomerular classification in class I (P = .006) and arteriolar hyalinosis score of 0 (P = .005). The renal survival among the three groups was comparable (P>.05).Conclusion: This study indicated that there were different clinicopathologic features among Chinese DN patients in different age groups. Although the Youth group had a relatively lower rapid kidney disease progression rate, there were no significant differences in renal survival rate among the three groups, which calls more attention to early supervision and prevention for younger DN patients.Abbreviations: CKD = chronic kidney disease; DN = diabetic nephropathy; DR = diabetic retinopathy; eGFR = estimated glomerular filtration rate; ESRD = end-stage renal disease; G&Y&O = green and yellow and orange; IFTA = interstitial fibrosis and tubular atrophy; T2DM = type 2 diabetes mellitus     

Need for research on estrogen receptor function: Importance for postmenopausal hormone therapy and atherosclerosis

Background: Cardiovascular disease is the leading cause of morbidity and mortality in men and women worldwide. Although rare in premenopausal women, its incidence rises sharply after menopause, indicating atheroprotective effects of endogenous estrogens.Objective: This review discusses the differential effects of estrogen receptor function on atherosclerosis progression in pre- and postmenopausal women, including aspects of gender differences in vascular physiology of estrogens and androgens.Methods: Recent advances in the understanding of the pathogenesis of atherosclerosis, estrogen receptor function, and hormone therapy are reviewed, with particular emphasis on clinical and molecular issues.Results: Whether hormone therapy can improve cardiovascular health in postmenopausal women remains controversial. Current evidence suggests that the vascular effects of estrogen are affected by the stage of reproductive life, the time since menopause, and the extent of subclinical atherosclerosis. The mechanisms of vascular responsiveness to sex steroids during different stages of atherosclerosis development remain poorly understood in women and men.Conclusion: In view of the expected increase in the prevalence of atherosclerotic vascular disease worldwide due to population aging, research is needed to determine the vascular mechanism of endogenous and exogenous sex steroids in patients with atherosclerosis. Such research may help to define new strategies to improve cardiovascular health in women and possibly also in men.     

The Association of Serum Bilirubin on Kidney Clinicopathologic Features and Renal Outcome in Patients with Diabetic Nephropathy: A Biopsy-Based Study

Objective: To explore the relationship between serum bilirubin concentration and clinicopathologic features and renal outcome in biopsy-diagnosed diabetic nephropathy (DN) in patients with type 2 diabetes mellitus.Methods: In this retrospective study, 118 patients with DN were enrolled. Participants were divided into two groups according to their median baseline serum bilirubin concentration: Group 1 (serum bilirubin ≤7.5 μmol /L); Group 2 (serum bilirubin >7.5 μmol /L). Basic clinical parameters were measured at the time of renal biopsy, and the relationships between serum bilirubin and the clinicopathologic features and renal outcome were analyzed.Results: Patients in Group 1 often had inferior renal function. Compared with Group 2, the glomerular classification and interstitial inflammation were more severe in subjects of Group 1, while arteriolar hyalinosis and interstitial fibrosis and tubular atrophy (IFTA) were comparable between the groups. Serum bilirubin was negatively correlated with the severity of the glomerular classification, interstitial inflammation, and IFTA. In the prognostic analysis, higher serum bilirubin level was associated with a lower risk of progression to end-stage renal disease, which was independent of the effects of age, gender, duration of diabetes, anemia, serum glucose, and hypertension but not of estimated glomerular filtration rate (hazard ratio, 0.406; 95% confidence interval, 0.074 to 2.225; P = .299).Conclusion: Our study showed a negative correlation between serum bilirubin level and renal pathologic lesions in patients with DN; serum bilirubin showed an inverse association with DN progression, but this was not independent.Abbreviations: CI = confidence interval; CKD = chronic kidney disease; DM = diabetes mellitus; DN = diabetic nephropathy; DR = diabetic retinopathy; eGFR = estimated glomerular filtration rate; ESRD = end-stage renal disease; HbA1c = glycated hemoglobin; HO-1 = heme oxygenase 1; HR = hazard ratio; IFTA = interstitial fibrosis and tubular atrophy; log-BIL = log-transformed baseline serum bilirubin; T2DM = type 2 diabetes mellitus     

Diabetic Retinopathy,Classified Using the Lesion-Aware Deep Learning System,Predicts Diabetic End-Stage Renal Disease in Chinese Patients

Objective: To characterize the relationship between diabetic retinopathy (DR) and diabetic nephropathy (DN) in Chinese patients and to determine whether the severity of DR predicts end-stage renal disease (ESRD).Methods: Bilateral fundic photographs of 91 Chinese type 2 diabetic patients with biopsy-confirmed DN, not in ESRD stage, were obtained at the time of renal biopsy in this longitudinal study. The baseline severity of DR was determined using the Lesion-aware Deep Learning System (RetinalNET) in an open framework for deep learning and was graded using the Early Treatment Diabetic Retinopathy Study severity scale. Cox proportional hazard models were used to estimate the hazard ratio (HR) for the effect of the severity of diabetic retinopathy on ESRD.Results: During a median follow-up of 15 months, 25 patients progressed to ESRD. The severity of retinopathy at the time of biopsy was a prognostic factor for progression to ESRD (HR 2.18, 95% confidence interval 1.05 to 4.53, P = .04). At baseline, more severe retinopathy was associated with poor renal function, and more severe glomerular lesions. However, 30% of patients with mild retinopathy and severe glomerular lesions had higher low-density lipo-protein-cholesterol and more severe proteinuria than those with mild glomerular lesions. Additionally, 3% of patients with severe retinopathy and mild glomerular changes were more likely to have had diabetes a long time than those with severe glomerular lesions.Conclusion: Although the severity of DR predicted diabetic ESRD in patients with type 2 diabetes mellitus and DN, the severities of DR and DN were not always consistent, especially in patients with mild retinopathy or microalbuminuria.Abbreviations: CI = confidence interval; DM = diabetic mellitus; DN = diabetic nephropathy; DR = diabetic retinopathy; eGFR = estimated glomerular filtration rate; ESRD = end-stage renal disease; HbA1c = hemoglobin A1c; HR = hazard ratio; NPDR = nonproliferative diabetic retinopathy; PDR = proliferative diabetic retinopathy; SBP = systolic blood pressure; T2DM = type 2 diabetes mellitus; VEGF = vascular endothelial growth factor     

Sex steroids and vascular responses in hypertension and aging

Background: Sex hormones play a significant role in human physiology. Estrogen may have protective effects in the cardiovascular system, as evidenced by the decreased incidence of cardiovascular disease (CVD) in premenopausal compared with postmenopausal women.Objective: This review highlights the acute and long-term effects of sex hormones on the vascular endothelium and vascular smooth muscle (VSM) in adults. Changes in the sex hormone mix, their receptors, and their effects on vascular function in hypertension and aging are also discussed.Methods: Literature collected from the National Centers for Biotechnology Information as identified by a PubMed database search, as well as our experimental work, was used to highlight current knowledge regarding vascular responses to sex hormones in hypertension and in aging.Results: Experiments in adult female animals have shown that estrogen induces endothelium-dependent vascular relaxation via the nitric oxide (NO), prostacyclin, and hyperpolarization pathways. Also, surface membrane estrogen receptors (ERs) decrease intracellular free Ca²⁺ concentration and perhaps protein kinase C-dependent VSM contraction. However, clinical trials such as the Heart and Estrogen/progestin Replacement Study (HERS), HERS-II, and the Women's Health Initiative did not support the experimental findings and demonstrated adverse cardiovascular events of hormone therapy (HT) in aging women. The lack of vascular benefits of HT may be related to the hormone used, the ER, or the patient's cardiovascular condition or age. Experiments on vascular strips from aging (16-month-old) female spontaneously hypertensive rats have shown reduced ER-mediated NO production from endothelial cells and decreased inhibitory effects of estrogen on Ca²⁺ entry mechanisms of VSM contraction. The age-related decrease in ER-mediated vascular relaxation may explain the decreased effectiveness of HT on CVD in aging women.Conclusions: New HT strategies should further examine the benefits of natural estrogens and phytoestrogens. Transdermal estrogen may be more effective than the oral form, and specific ER modulators may maximize the vascular benefits and reduce the risk of invasive breast cancer. Variants of vascular ERs should be screened for genetic polymorphisms and postmenopausal decrease in the amount of downstream signaling mechanisms. HT may be more effective during the menopausal transition than in late menopause. Progesterone, testosterone, or their specific modulators may be combined with estrogen to provide alternative HT strategies. Thus, HT type, dose, route of administration, and timing should be customized, depending on the patient's cardiovascular condition and age, thereby enhancing the vascular benefits of HT in aging women.     

Drug-induced long QT syndrome in women: Review of current evidence and remaining gaps

Background: Women are at an increased risk of drug-induced long QT syndrome (LQTS). This major cardiac adverse effect may lead to malignant polymorphic ventricular tachycardias, termed torsades de pointes, which may degenerate into ventricular fibrillation and cause sudden death.Objective: This article reviews current evidence and remaining gaps in knowledge about drug-induced LQTS in women.Methods: Using the search terms gender, sex, and sex differences in combination with cardiac electrophysiology, long QT syndrome, HERG, membrane transporters, and cytochromes, we conducted a systematic review of the available literature in the PubMed database. Relevant English- and French-language publications (to October 2007) on sex differences in LQTS were identified.Results: Clinical and experimental studies have reported that gonadal hormones play a role in sex-related differences of QT interval prolongation. Androgens may diminish drug effects on heart repolarization, and estrogens may facilitate arrhythmias. Furthermore, sex-related differences in the density of ion channels may partially explain this phenomenon. However, the magnitude of hormone-dependent differences observed in these studies remains very small compared with the large differences observed in clinical settings. Therefore, many scientists agree that the mechanisms responsible for sex-related differences in the risk of proarrhythmia from drugs remain largely undefined.Conclusions: Other factors, such as sex-related modulation of drug disposition in situ, may fill the gaps in our understanding of the sex differences observed in drug-induced LQTS. We suggest that mechanisms such as the modulation of the pharmacokinetics of I_Kr (rapid component of the delayed rectifier potassium current) blockers, via modulation of intra- and extracellular concentrations, may be of major importance. Sex-specific changes in drug transport and metabolism will result in different plasma and intracellular levels acting along a dose-response effect on I_Kr block. Consequently, important hormone-dependent factors such as metabolic enzymes and membrane transporters need to be investigated in new basic research studies.     

Sex Differences in Hypertension: Contribution of the Renin–Angiotensin System

Numerous studies have shown that female human beings exhibit lower blood pressure levels over much of their life span compared with their age-matched counterparts. This sexual dimorphism is apparent in human beings as well as most, if not all, mammals. However, after the onset of menopause blood pressure levels in women increase and become similar to those in men, suggesting an important role of sex hormones in the regulation of blood pressure. The lower blood pressure levels in premenopausal women are associated with a lower risk of development and progression of cardiovascular disease and hypertension compared with age-matched men. This clear female advantage with respect to lower incidence of cardiovascular disease no longer exists after menopause, again highlighting the importance of sex hormones in the pathophysiology of cardiovascular disease in both men and women. In fact, both estrogens and androgens have been implicated in the development of cardiovascular disease and hypertension, with estrogens, in general, being protective and androgens being detrimental. Although the exact mechanisms by which sex hormones contribute to the regulation of cardiovascular function and blood pressure are still being investigated, there is increasing evidence that modulating the activity of locally active hormonal systems is one of the major mechanisms of sex hormone actions in target organs, including the vasculature and kidneys. Indeed, several studies have demonstrated the importance of the interaction between sex hormones and the renin–angiotensin system in regulating cardiovascular function and blood pressure. Furthermore, the differential effects of estrogens and androgens on the expression and activity of the components of the renin–angiotensin system could possibly explain the sex differences in blood pressure levels and the development and progression of cardiovascular disease and hypertension.     

Estrogen receptors in the kidney: Lessons from genetically altered mice

Background: Sex differences in human and animal models of kidney disease suggest that estrogen receptor (ER)-mediated events may modulate these processes. Genetically altered mice lacking one or both ERs provide a powerful tool to study these phenomena.Objective: This article examines sex differences in the kidney, particularly the role of ERs.Methods: To identify pertinent studies in genetically altered mice, a literature search was conducted on the MEDLINE database from January 1966 to July 2007, using the search terms estrogen receptor, kidney, and mice. Our group examined the effect of the ER-α knockout genotype on the kidney in streptozotocin-induced diabetes mellitus and compensatory kidney growth after uninephrectomy.Results: Female mice lacking ERa had reduced renal growth, including glomerular enlargement after 2 weeks of streptozotocin-induced diabetes mellitus and compensatory kidney growth 48 hours after uninephrectomy.Conclusion: ER-mediated events influence kidney growth and disease in female mice.     

The Clinical And Metabolic Characteristics Of Young-Onset Ketosis-Prone Type 2 Diabetes In China

Objective: To investigate the prevalence and clinical characteristics of ketosis-prone type 2 diabetes (KPD) in Chinese patients with young-onset diabetes.Methods: A total of 238 young diabetic patients were recruited from our inpatient department from January 1, 2012, to December 28, 2014. KPD was defined as diabetes without precipitating illness and with the presence of ketosis or diabetic ketoacidosis in the absence of autoantibodies at the time of diagnosis. We reviewed the clinical characteristics and disease progression of this group of patients.Results: Eighteen patients fulfilled the criteria for KPD, and the prevalence of patients with KPD was 7.6%. The mean (SD) age of the KPD group at the time of diagnosis of diabetes was 27.6 (4.85) years, and these patients were predominantly male (male to female ratio, 8:1) and had a high proportion of obesity and new-onset diabetes and a strong family history of diabetes. β-Cell function in the KPD group was intermediate between type 1 and type 2 diabetes. Patients with KPD had the highest levels of glycated hemoglobin, triglycerides, total cholesterol, and free fatty acids and the lowest levels of high-density lipoprotein. After 3 to 12 months of follow-up, 17 of 18 patients with KPD (94.4%) were able to discontinue insulin therapy, and 11 patients (61.1%) were managed with diet or exercise alone.Conclusion: KPD patients accounted for 7.6% of the diabetic patients requiring admission to a large urban hospital in China, with an age of onset of diabetes of ≤35 years. These patients are more likely to be male, have abnormal lipid metabolism, and have more reversible β-cell dysfunction.Abbreviations:BMI = body mass indexDKA = diabetic ketoacidosisGAD 65 = glutamate decarboxylase 65HbA _1c = glycated hemoglobinICAs = islet-cell antibodiesKPD = ketosis-prone type 2 diabetes mellitusLADA = latent autoimmune diabetes in an adultMIDD = maternally inherited diabetes and deafnessMODY = maturityonset diabetes of the youngT1DM = type 1 diabetes mellitusT2DM = type 2 diabetes mellitus     

Female protection in progressive renal disease is associated with estradiol attenuation of superoxide production

Background: Several types of renal disease progress at a faster rate in men compared with women, but the reasons for this sex difference are not well understood. Chronic renal disease is associated with elevated levels of toxic reactive oxygen species (ROS). Superoxide, the major ROS in the kidney, is generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase.Objective: To determine if female protection from renal disease progression is consistent with 17β-estradiol (E₂) attenuation of superoxide production, this study was conducted to assess superoxide production in the renal cortex of male and female control and renal wrap (RW) rats, as well as in ovariectomized rats treated with vehicle or E₂.Methods: Sprague-Dawley rats were divided into 2 sham operation male (Sham-M) and female (Sham-F) control groups, and 4 RW hypertensive groups: RW-M; RW-F; RW ovariectomized females treated with vehicle (RW-OVX); and RW ovariectomized females treated with E₂, supplied as a 0.24 mg/60-day release pellet (RW-OVX+E₂). All groups were maintained on a high-sodium (4% NaCl) diet for 6 weeks.Results: Mean (SEM) markers of renal injury and oxidative stress, including urinary protein (mg/24 h: RW-M, 298 [31] vs RW-F, 169 [22]; P < 0.001), microalbuminuria (RW/Sham arbitrary units [AU]/24 h: M, 8.78 [0.58] vs F, 4.31 [1.0]; P < 0.005), and malondialdehyde (nmol/24 h: RW-M, 167 [23] vs RW-F, 117 [8.5]; P < 0.05) levels, as well as mean glomerular volume (μm³ × 10⁶: RW-M, 2.25 [0.16] vs RW-F, 1.25 [0.04]; P < 0.001) and the glomerulosclerotic index (AU: RW-M, 2.64 [0.19] vs RW-F, 1.10 [0.09]; P < 0.001) were greater in both control and RW males compared with females in the same treatment groups. Though RW surgery increased mean arterial pressure in both male and female rats, no sex difference was observed. Under these conditions, mean (SEM) renal cortical NADPH oxidase activity was 1.3-fold higher in RW males compared with RW females (relative light units [RLU]/180 sec: RW-M, 4080 [240] vs RW-F, 3200 [260]; P < 0.05). Ovariectomy increased NADPH oxidase activity by 1.4-fold (RLU/180 sec: RW-OVX, 4520 [184]; P < 0.01) under conditions in which the mean glomerular volume and glomerulosclerotic index were both increased by 1.5-fold, whereas E₂ replacement (RLU/180 sec: RW-OVX+E₂, 2745 [440]) prevented these effects. Furthermore, the effects on NADPH oxidase activity were mirrored by changes in the protein abundance of NADPH oxidase subunit p22P^phox.Conclusion: These results suggest that E₂ protects the female kidney in part by attenuating injury-induced increases in renal superoxide production.     

Axial BMD in Diabetic and Nondiabetic Southeast Asians with HIP Fractures: Do Race and Body Mass Index Matter?

Objective: Obesity is less prevalent in Asian subjects with type 2 diabetes mellitus (T2DM) in contrast to Caucasians. Whether higher axial bone mineral density (BMD) often reported in T2DM is independent of body mass index (BMI) has not been clearly shown. BMD characterization in T2DM patients with hip fractures has also not been performed. We compared the BMD of Asian diabetic and nondiabetic patients with new hip fractures and explored how BMD was influenced by BMI.Methods: We included 255 diabetic and 148 nondiabetic patients. BMD adjusted for age; BMI; race; sex; renal function; and use of statins, proton pump inhibitors, steroids, anticonvulsants, and calcium and/or vitamin D supplements were compared between the groups. We were particularly interested in the BMD comparison between underweight diabetics and nondiabetics with hip fractures.Results: The presence of T2DM was associated with higher BMD (g/cm²) at the femoral neck (0.527 ± 0.103 vs. 0.491 ± 0.102, P<.01) and lumbar spine [LS] (0.798 ± 0.147 vs. 0.723 ± 0.156, P<.01). This association persisted after adjustment for multiple confounding variables including BMI. The age-, BMI-, and sex-adjusted LS BMD was higher in underweight (BMI <18.5 kg/m²) diabetics compared to similar weight nondiabetics (0.733 ± 0.126 vs. 0.649 ± 0.131 g/cm², P = .014).Conclusion: T2DM is independently associated with higher axial BMD in patients with new hip fractures. The finding of higher BMD even in underweight diabetics with hip fractures compared to their nondiabetic counterparts suggests that higher BMD in subjects with T2DM is not due to higher BMI.Abbreviations:BMD = bone mineral densityBMI = body mass indexCV = coefficient of variationDXA = dual-energy X-ray absorptiometryHbA1c = glycated hemoglobinIGF-1 = insulin growth factor-1LS = lumbar spine25(OH)D = 25-hydroxyvitamin DT2DM = type 2 diabetes mellitus     

Review of cardiovascular risk factors in women

Background: Although cardiovascular disease (CVD) is the leading cause of death in women in the United States, a knowledge gap persists regarding the mechanisms and management of CVD in women. Before treatment can be optimized, the role of cardiovascular risk factors must be elucidated.Objective: This review provides an updated assessment of cardiovascular risk factors in women, with a focus on cardiometabolic risk.Methods: MEDLINE and Cochrane Library databases, and statistics from the National Health and Nutrition Examination Survey and the American Heart Association, were searched from 1990 to September 2008 using the following terms: cardiovascular risk factors, women, gender, cardiometabolic risk, abdominal obesity, and metabolic syndrome. Publications were classified as English-only original data, reviews, and clinical guidelines. Nonpublished data were excluded. Data were extracted by 2 reviewers independently.Results: Investigators performing multivariable predictive models have estimated that traditional risk factors account for ~70% of the variance in estimating cardiovascular events. However, substantial sex differences exist in the prevalence of traditional risk factors as well as in cardiovascular outcomes. Hypertension is more prevalent in men until the age of 59 years, but then contributes to greater morbidity in older women. Low levels of high-density lipoprotein and elevated triglyceride levels pose more of a threat to women, yet high levels of low-density lipoprotein pose equal risk for women and men. The CVD mortality rate is -3 times greater in people with diabetes than in those without diabetes. Among diabetic individuals, CVD mortality is slightly higher in women compared with men.Conclusions: Increased knowledge of gender-specific risks for CVD has led to national campaigns to educate women. In addition to traditional risk factors, cardiometabolic risk is an important consideration in women. Controversy exists regarding the exact definitions and usefulness of the term metabolic syndrome, but it is clear that the presence of certain factors contributes to increased morbidity and mortality in affected individuals. Abdominal obesity links insulin resistance, dyslipidemia, and hypertension through complex endocrine pathways. Current research is identifying gene × gender interactions, and continued research is necessary to explore the relationship of sex steroids and cardiovascular risk in both men and women.     

Family History of Diabetes is Associated with Increased Risk of Recurrent Diabetic Ketoacidosis in Pediatric Patients

Objective: To determine the relationship between family history of diabetes mellitus (DM) and diabetic ketoacidosis (DKA) recurrence in youth with established type 1 diabetes mellitus (T1DM).Methods: We performed a retrospective chart review of patients with DKA admitted to a pediatric hospital between January, 2009, and December, 2014. We compared patients with recurrent (≥2 admissions) and nonrecurrent DKA (1 admission) and investigated patient level factors, including family history, that may be associated with DKA recurrence in pediatric patients with established T1DM.Results: Of the 131 subjects in the study, 51 (39%) subjects were in the recurrence group. Age ≥15 years old, public health insurance, and family history of T1DM or type 2 diabetes mellitus were associated with recurrent DKA admissions in both univariable and multivariable analyses. Family history was associated with DKA recurrence, with an incidence rate ratio of 1.5 (95% confidence interval = 1.0 to 2.3; P = .03). The association was not explained by type of familial diabetes, first degree relative status, or whether the family member lived in the household.Conclusion: Recognition that a positive family history of DM may be associated with a higher risk for DKA recurrence in patients with established T1DM may allow for targeted education and focus on a previously unidentified population at increased risk for DKA. Understanding the mechanism underlying the effect of family history of diabetes on the rates of DKA in patients with established T1DM may allow for improved identification and education of patients who may be at risk for DKA recurrence.Abbreviations: CI = confidence interval; DKA = diabetic ketoacidosis; EHR = electronic health record; IBD = inflammatory bowel disease; IRR = incidence rate ratio; T1DM = type 1 diabetes mellitus; T2DM = type 2 diabetes mellitus     

Rosiglitazone Treatment of Type 2 Diabetic db/db Mice Attenuates Urinary Albumin and Angiotensin Converting Enzyme 2 Excretion

Alterations within the renal renin angiotensin system play a pivotal role in the development and progression of cardiovascular and renal disease. Angiotensin converting enzyme 2 (ACE2) is highly expressed in renal tubules and has been shown to be renoprotective in diabetes. The protease, a disintegrin and metalloprotease (ADAM) 17, is involved in the ectodomain shedding of several transmembrane proteins including ACE2. Renal ACE2 and ADAM17 were significantly increased in db/db mice compared to controls. We investigated the effect of the insulin sensitizer, rosiglitazone, on albuminuria, renal ADAM17 protein expression and ACE2 shedding in db/db diabetic mice. Rosiglitazone treatment of db/db mice normalized hyperglycemia, attenuated renal injury and decreased urinary ACE2 and renal ADAM17 protein expression. Urinary excreted ACE2 is enzymatically active. Western blot analysis of urinary ACE2 demonstrated two prominent immunoreactive bands at approximately 70 & 90 kDa. The predominant immunoreactive band is approximately 20 kDa shorter than the one demonstrated for kidney lysate, indicating possible ectodomain shedding of active renal ACE2 in the urine. Therefore, it is tempting to speculate that renoprotection of rosiglitazone could be partially mediated via downregulation of renal ADAM17 and ACE2 shedding. In addition, there was a positive correlation between blood glucose, urinary albumin, plasma glucagon, and triglyceride levels with urinary ACE2 excretion. In conclusion, urinary ACE2 could be used as a sensitive biomarker of diabetic nephropathy and for monitoring the effectiveness of renoprotective medication.