Molybdenum Complexes of Chiral C2-symmetric Picchxn-type Ligands: Synthesis, Characterization, and Structural Studies

A series of molybdenum complexes based on chiral C2-symmetric picchxn-type ligands (N4 ligands, defined as trans-N,N′-bis(heterocycl-2-ylmethyl)-1,2-diaminocyclohexanes) has been synthesized and characterized. Reported and novel picchxn-type ligands form (κ3-N4)Mo(CO)3, [(κ4-N4)Mo(NO)(CO)]PF6, and [(κ4-N4)Mo(NO)X]PF6 (X = Br, I) compounds. Multiple tridentate (κ3) and tetradentate (κ4) ligand configurations were observed, and the favored κ4 configuration was found to vary with N4 heterocycle identity. Heterocycle variation allowed for directed modification of the molybdenum electronic characteristics, but none of the studied {(κ4-N4)Mo(NO)}+ fragments was found to be a suitable π-base for dearomatization chemistry. The crystal structures of eight molybdenum complexes with picchxn-type ligands were determined

Changes in insulin sensitivity over time and associated factors in HIV-infected adolescents

OBJECTIVE: To compare prevalence of insulin resistance between perinatally HIV-infected (PHIV+) and perinatally HIV-exposed, but uninfected adolescents (PHEU), determine incidence of and contributory factors to new and resolved cases of insulin resistance in PHIV+, and evaluate glucose metabolism. DESIGN: Cross-sectional design for comparison of prevalence among PHIV+ and PHEU. Longitudinal design for incidence and resolution of insulin resistance among PHIV+ at risk for these outcomes. METHODS: The source population was adolescents from pediatric HIV clinics in the United States and Puerto Rico participating in the Pediatric HIV/AIDS Cohort Study, an ongoing prospective cohort study designed to evaluate impact of HIV infection and its treatment on multiple domains in preadolescents and adolescents. Insulin resistance was assessed by homeostatic model assessment of insulin resistance. Those with incident insulin resistance underwent 2-h oral glucose tolerance test and HbA1c. Baseline demographic, metabolic, and HIV-specific variables were evaluated for association with incident or resolved insulin resistance. RESULTS: Unadjusted prevalence of insulin resistance in PHIV+ was 27.3 versus 34.1% in PHEU. After adjustment for Tanner stage, age, sex, and race/ethnicity, there was no significant difference between groups. Factors positively associated with developing insulin resistance included female sex, higher BMI z score, and higher waist circumference; those associated with resolving insulin resistance included male sex and lower BMI z score. CONCLUSION: Prevalence of insulin resistance in PHIV+ and PHEU was substantially higher than that reported in HIV-uninfected nonoverweight youth, but similar to that in HIV-uninfected obese youth. Factors associated with incident or resolved insulin resistance among PHIV+ were similar to those reported in HIV-negative obese youth. However, a contributory role of HIV infection and/or its treatment to the incident risk of insulin resistance cannot be excluded

The Women’s Leadership Gap in Diabetes: A Call for Equity and Excellence

Women are broadly underrepresented in scientific leadership positions and their accomplishments are not provided equal recognition compared with those of men, but the imbalance in the field of diabetes is unknown. Hence, we analyzed multiple aspects of historical and present-day female representation in the diabetes field.We quantified gender representation at annual American Diabetes Association (ADA) meetings; editorial board service positions for ADA and the European Association for the Study of Diabetes (EASD) journals; principal investigators for ADA, JDRF, and National Institutes of Health National Institute of Diabetes and Digestive and Kidney Diseases P30 grant funding; and ADA, JDRF, and EASD award recipients. There are many women in the field of diabetes: registration for the ADA Scientific Sessions has been 43% female since 2016, and for over five decades, women comprised 83% of ADA Presidents of Health Care and Education. Yet, only 9% of ADA Presidents of Medicine and Science have been women. Women were well represented on editorial boards for journals focused on diabetes education (Diabetes Spectrum, 89% female) and primary care (Clinical Diabetes, 49% female) but not for the more academically targeted Diabetes Care (34% female), Diabetes (21% female), and Diabetologia (30% female). Only one-third of ADA Pathway to Stop Diabetes and JDRF grants have been awarded to women, and females only lead 2 of 18 (11%) of the P30-supported Diabetes Research Centers. Finally, only 2–12% of major ADA, JDRF, and EASD awards were given to women, without significant change over time. Despite increasing recognition of gender imbalance in research and medicine, many disparities in the field of diabetes persist. We call for decreasing barriers for advancement of female investigators and creating environments that promote their retention and equitable recognition for their contributions to the field

Proinsulin Secretion Is a Persistent Feature of Type 1 Diabetes

OBJECTIVE: Abnormally elevated proinsulin secretion has been reported in type 2 and early type 1 diabetes when significant C-peptide is present. We questioned whether individuals with long-standing type 1 diabetes and low or absent C-peptide secretory capacity retained the ability to make proinsulin. RESEARCH DESIGN AND METHODS: C-peptide and proinsulin were measured in fasting and stimulated sera from 319 subjects with long-standing type 1 diabetes (≥3 years) and 12 control subjects without diabetes. We considered three categories of stimulated C-peptide: 1) C-peptide positive, with high stimulated values ≥0.2 nmol/L; 2) C-peptide positive, with low stimulated values ≥0.017 but <0.2 nmol/L; and 3) C-peptide <0.017 nmol/L. Longitudinal samples were analyzed from C-peptide-positive subjects with diabetes after 1, 2, and 4 years. RESULTS: Of individuals with long-standing type 1 diabetes, 95.9% had detectable serum proinsulin (>3.1 pmol/L), while 89.9% of participants with stimulated C-peptide values below the limit of detection (<0.017 nmol/L; n = 99) had measurable proinsulin. Proinsulin levels remained stable over 4 years of follow-up, while C-peptide decreased slowly during longitudinal analysis. Correlations between proinsulin with C-peptide and mixed-meal stimulation of proinsulin were found only in subjects with high stimulated C-peptide values (≥0.2 nmol/L). Specifically, increases in proinsulin with mixed-meal stimulation were present only in the group with high stimulated C-peptide values, with no increases observed among subjects with low or undetectable (<0.017 nmol/L) residual C-peptide. CONCLUSIONS: In individuals with long-duration type 1 diabetes, the ability to secrete proinsulin persists, even in those with undetectable serum C-peptide

Markers of Bone Mineral Metabolism and Cardiac Structure and Function in Perinatally HIV-Infected and HIV-Exposed but Uninfected Children and Adolescents

Background: Disordered bone mineral metabolism and low vitamin D concentrations are associated with cardiovascular abnormalities; few studies have evaluated this relationship in HIV-infected youth. Setting: Adolescent Master Protocol (AMP) is a Pediatric HIV/AIDS Cohort Study (PHACS) network study conducted across 14 United States sites. Methods: Among perinatally HIV-infected (PHIV) and HIV-exposed uninfected (PHEU) youth enrolled in AMP, we evaluated associations of vitamin D (measured as 25-hydroxyvitamin D [25OHD]), parathyroid hormone (PTH), calcium, phosphate, and fibroblast growth factor-23 (FGF-23) concentrations with echocardiographic measures of left ventricular (LV) structure, function and concentrations of NT-proBNP, a biomarker of cardiac damage. Results: Among 485 participants (305 PHIV, 180 PHEU) with echocardiograms and bone mineralization measures, low 25OHD ( 65 pg/mL) was identified more often among PHIV than PHEU participants (9% vs 3%, p=0.02). After adjusting for HIV status and demographic covariates, both low 25OHD and elevated PTH were associated with lower mean LV mass z-scores, while elevated PTH was associated with higher mean fractional shortening z-scores. Participants with low 25OHD also had slightly higher mean LV end-systolic wall stress z-scores, but differences were more pronounced in PHEU than in PHIV participants. FGF-23 was inversely related to end-diastolic septal thickness both overall and among PHIV participants. Conclusion: In this cohort of PHIV and PHEU youth, we observed associations of 25OHD, PTH, and FGF-23 with both structural and functional cardiac parameters, supporting links between bone mineral metabolism and cardiac status

Gender differences in diabetes self-care in adults with type 1 diabetes: Findings from the T1D Exchange clinic registry

Aims To evaluate gender differences in diabetes self-care components including glycemic, blood pressure and lipid control, utilization of diabetes technologies and acute diabetes complications in adults with type 1 diabetes. Methods A total of 9,481 participants >18 years were included in the analysis, 53% were female. Variables of interest included glycemic control measured by HbA1c, systolic/diastolic blood pressures, presence of dyslipidemia, insulin delivery modality, and rates of acute complications. Results Glycemic control was similar in women and men (mean HbA1c in both groups: 8.1% ± 1.6% (64 ± 16 mmol/mol), (p = 0.54). More women used insulin pump therapy (66% vs. 59%, p < 0.001) but use of sensor technology was similar (p < = 0.42). Women had higher rates of diabetic ketoacidosis (DKA) (5% vs. 3%, p < 0.001) and eating disorders (1.7% vs. 0.1%, p < 0.001). Severe hypoglycemia rates were not different between men and women (p = 0.42). Smoking (6% vs 4%, p < 0.001), systolic (125 ± 14.2 vs. 121 ± 14.4, p < 0.001) and diastolic blood pressure (73.3 ± 9.5 vs. 72.2 ± 9.3, p < 0.001) and rate of dyslipidemia (28% vs. 23%, p < 0.001) were higher in men. Conclusion While glycemic control in type 1 diabetes was similar regardless of gender, rates of DKA and eating disorders were higher in women while rates of smoking, hypertension and dyslipidemia were higher in men

Associations of Low Vitamin D and Elevated Parathyroid Hormone Concentrations With Bone Mineral Density in Perinatally HIV-Infected Children

BACKGROUND: Perinatally HIV-infected (PHIV) children have, on average, lower bone mineral density (BMD) than perinatally HIV-exposed uninfected (PHEU) and healthy children. Low 25-hydroxy vitamin D [25(OH)D] and elevated parathyroid hormone (PTH) concentrations may lead to suboptimal bone accrual. METHODS: PHIV and PHEU children in the Pediatric HIV/AIDS Cohort Study had total body (TB) and lumbar spine (LS) BMD and bone mineral content (BMC) measured by dual-energy x-ray absorptiometry; BMD z-scores (BMDz) were calculated for age and sex. Low 25(OH)D was defined as ≤20 ng/mL and high PTH as >65 pg/mL. We fit linear regression models to estimate the average adjusted differences in BMD/BMC by 25(OH)D and PTH status and log binomial models to determine adjusted prevalence ratios of low 25(OH)D and high PTH in PHIV relative to PHEU children. RESULTS: PHIV children (n = 412) were older (13.0 vs. 10.8 years) and more often black (76% vs. 64%) than PHEU (n = 207). Among PHIV, children with low 25(OH)D had lower TB-BMDz [SD, -0.38; 95% confidence interval (CI), -0.60 to -0.16] and TB-BMC (SD, -59.1 g; 95% CI, -108.3 to -9.8); high PTH accompanied by low 25(OH)D was associated with lower TB-BMDz. Among PHEU, children with low 25(OH)D had lower TB-BMDz (SD, -0.34; 95% CI, -0.64 to -0.03). Prevalence of low 25(OH)D was similar by HIV status (adjusted prevalence ratio, 1.00; 95% CI, 0.81 to 1.24). High PTH was 3.17 (95% CI, 1.25 to 8.06) times more likely in PHIV children. CONCLUSIONS: PHIV and PHEU children with low 25(OH)D may have lower BMD. Vitamin D supplementation trials during critical periods of bone accrual are needed

Delay in sexual maturation in perinatally HIV-infected youths is mediated by poor growth

OBJECTIVE: To evaluate the association between HIV infection and sexual maturation, and mediation of this association by HIV effects on growth. DESIGN: Pooled data were analyzed from two longitudinal cohort studies, the International Maternal Pediatric Adolescent AIDS Clinical Trials P219/219C Study (1993-2007) and the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol (2007-2015), including perinatally HIV-infected (PHIV) and HIV-exposed uninfected (PHEU) youths. METHODS: We evaluated age at sexual maturity among 2539 PHIV and PHEU adolescents based on annual physician-assessed pubertal staging measures. Interval-censored regression models were used to evaluate associations of HIV infection with age at maturity. Mediation analyses accounting for height and BMI Z-scores at specific ages were used to estimate direct and indirect effects of HIV infection on age at sexual maturity. RESULTS: Mean ages at sexual maturity for PHIV girls (n = 1032) were 15.5 years for both female breast and pubic hair and 15.9 and 15.8 years for PHIV boys (n = 1054) for genitalia and pubic hair, respectively. PHIV youths matured approximately 6 months later on average than PHEU (n = 221 girls and 232 boys), and this difference persisted after adjustment for race/ethnicity and birth cohort. BMI and height Z-scores mediated the association between HIV infection and later maturation in girls, accounting for up to 74% of the total HIV effect. Only height Z-scores mediated the effect of HIV on male age at maturity, accounting for up to 98% of the HIV effect. CONCLUSION: PHIV youths attain sexual maturity later on average than PHEU youths. Much of this difference may be attributable to deficient growth, suggesting directions for future interventions