Advances in human oxytocin measurement: challenges and proposed solutions.

Oxytocin, a neuropeptide known for its role in reproduction and socioemotional processes, may hold promise as a therapeutic agent in treating social impairments in patient populations. However, research has yet to uncover precisely how to manipulate this system for clinical benefit. Moreover, inconsistent use of standardized and validated oxytocin measurement methodologies-including the design and study of hormone secretion and biochemical assays-present unresolved challenges. Human studies measuring peripheral (i.e., in plasma, saliva, or urine) or central (i.e., in cerebrospinal fluid) oxytocin concentrations have involved very diverse methods, including the use of different assay techniques, further compounding this problem. In the present review, we describe the scientific value in measuring human endogenous oxytocin concentrations, common issues in biochemical analysis and study design that researchers face when doing so, and our recommendations for improving studies using valid and reliable methodologies.

Loneliness, Methamphetamine Use, and Cardiovascular Risk Factors Among Sexual Minority Men in the COVID-19 Era.

BACKGROUND: Important gaps exist in our understanding of loneliness and biobehavioral outcomes among sexual minority men (SMM), such as faster HIV disease progression. At the same time, SMM who use methamphetamine are approximately one-third more likely than non-users to develop cardiovascular disease. This study examined associations of loneliness, stimulant use, and cardiovascular risk in SMM with and without HIV. METHOD: Participants were enrolled from August 2020 to February 2022 in a 6-month prospective cohort study. The study leveraged self-report baseline data from 103 SMM, with a subset of 56 SMM that provided a blood sample to measure markers of cardiovascular risk. RESULTS: Loneliness showed negative bivariate associations with total cholesterol and LDL cholesterol in the cardiometabolic subsample (n = 56). SMM with methamphetamine use (t(101) = 2.03, p < .05; d = .42) and those that screened positive for a stimulant use disorder (t(101) = 2.07, p < .05; d = .46) had significantly higher mean loneliness scores. In linear regression analyses, negative associations of loneliness with LDL and total cholesterol were observed only among SMM who used methamphetamine. CONCLUSION: We observed lower cholesterol in SMM reporting loneliness and methamphetamine use. Thus, in addition to the observed associations of loneliness with cholesterol, there are important medical consequences of methamphetamine use including cardiovascular risk, higher HIV acquisition risk and progression, as well as stimulant overdose death. This cross-sectional study underscores the need for clinical research to develop and test interventions targeting loneliness among SMM with stimulant use disorders.

APOL1 risk variants affect podocyte lipid homeostasis and energy production in focal segmental glomerulosclerosis.

Lipotoxicity was recently reported in several forms of kidney disease, including focal segmental glomerulosclerosis (FSGS). Susceptibility to FSGS in African Americans is associated with the presence of genetic variants of the Apolipoprotein L1 gene (APOL1) named G1 and G2. If and how endogenous APOL1 may alter mitochondrial function by the modifying cellular lipid metabolism is unknown. Using transgenic mice expressing the APOL1 variants (G0, G1 or G2) under endogenous promoter, we show that APOL1 risk variant expression in transgenic mice does not impair kidney function at baseline. However, APOL1 G1 expression worsens proteinuria and kidney function in mice characterized by the podocyte inducible expression of nuclear factor of activated T-cells (NFAT), which we have found to cause FSGS. APOL1 G1 expression in this FSGS-model also results in increased triglyceride and cholesterol ester contents in kidney cortices, where lipid accumulation correlated with loss of renal function. In vitro, we show that the expression of endogenous APOL1 G1/G2 in human urinary podocytes is associated with increased cellular triglyceride content and is accompanied by mitochondrial dysfunction in the presence of compensatory oxidative phosphorylation (OXPHOS) complexes elevation. Our findings indicate that APOL1 risk variant expression increases the susceptibility to lipid-dependent podocyte injury, ultimately leading to mitochondrial dysfunction.

Health Care Provider Discussions Regarding HIV/Sexually Transmitted Infection Risk Factors and Associations with HIV/Sexually Transmitted Infection Screening Among Men.

Little is known regarding the specific discussions health care providers (HCP) have with their patients and how these discussions may increase rates of HIV/STI screening. The main objective of this study was to examine the content of HCP-patient discussions and associations with HIV/STI screening while adjusting for patient characteristics. Using the 2017-2019 National Survey of Family Growth data, seven survey-weighted multivariable multinomial/binary logistic regression models were analyzed in men ages 15-49 years old (N = 4260). Patients had significantly higher odds of a lifetime HIV test when their HCP asked about number of sexual partners (adjusted odds ratio [aOR] = 2.325; 95% CI 1.379-3.919) and discussed HIV/AIDS (aOR = 4.149; 95% CI 2.877-5.983). Odds of a recent STI screening were higher among patients with HCP that asked about: sexual orientation (aOR = 1.534; 95% CI 1.027-2.291), number of sexual partners (aOR = 2.123; 95% CI 1.314-3.430), use of condoms (aOR = 2.295 95% CI 1.484-3.548), type of sexual intercourse (aOR = 1.900; 95% CI 1.234-2.925), and discussed HIV/AIDS (aOR = 1.549; 95% CI 1.167-2.056). Results may provide insight on how HCPs may potentially promote HIV/AIDS and STI screening among men and which patient groups are more likely to receive a discussion of risks factors from their HCPs.

Positive Psychosocial Factors and Oxytocin in the Ovarian Tumor Microenvironment.

OBJECTIVE: Clinical ovarian cancer research shows relationships between psychosocial factors and disease-promoting aspects of the stress response (e.g., norepinephrine and cortisol). However, little is known about how psychosocial factors might relate to beneficial hormones in the ovarian tumor microenvironment. Here we examine relationships between psychosocial factors and tumor-associated oxytocin, a hormone linked to survival and antitumor processes in ovarian cancer. METHODS: Patients with ovarian cancer (n = 96) completed assessments of positive psychosocial factors (social support, positive affect, and purpose in life) and distress (perceived stress and depression) at the time of surgery. Levels of oxytocin and interleukin (IL) 6 in ascites fluid were obtained during surgery and analyzed by enzyme-linked immunosorbent assay. Multiple regression analyses adjusting a priori for patient age and disease stage examined associations between psychosocial factors and ascites oxytocin. IL-6 was used as a covariate in secondary analyses to examine the potentially confounding effects of inflammation in these relationships. RESULTS: Higher levels of positive affect (ß = 0.22, p = .034), purpose in life (ß = 0.31, p = .021), and social nurturance (ß = 0.24, p = .024) were all related to higher levels of tumor-associated oxytocin at the time of surgery. In contrast, we found no effects for distress or social attachment. Relationships between oxytocin, purpose in life, and social nurturance were independent of IL-6, whereas positive affect was no longer significant with IL-6 in the model. CONCLUSIONS: Tumor-associated oxytocin may be a previously uninvestigated link in the relationship between psychosocial factors and health in ovarian cancer. Future studies should examine causal mechanisms of relationships observed in this study.

Differences in Acute Metabolic Responses to Bionic and Nonbionic Ambulation in Spinal Cord Injured Humans and Controls.

OBJECTIVES: To (1) compare energy expenditure during seated rest, standing, and prolonged bionic ambulation or bipedal ambulation in participants with spinal cord injury (SCI) and noninjured controls, respectively, and (2) test effects on postbionic ambulation glycemia in SCI. DESIGN: Two independent group comparison of SCI and controls. SETTING: Academic Medical Center. PARTICIPANTS: Ten participants with chronic SCI (C7-T1, American Spinal Injury Association Impairment Scale A-C) and 10 controls (N=20). INTERVENTIONS: A commercial bionic exoskeleton. MAIN OUTCOME MEASURES: Absolute and relative (to peak) oxygen consumption, perceived exertion, carbohydrate/fat oxidation, energy expenditure, and postbionic ambulation plasma glucose/insulin. RESULTS: Average work intensity accompanying 45 minutes of outdoor bionic ambulation was <40% peak oxygen consumption, with negligible drift after reaching steady state. Rating of perceived exertion (RPE) did not differ between groups and reflected low exertion. Absolute energy costs for bionic ambulation and nonbionic ambulation were not different between groups despite a 565% higher ambulation velocity in controls and 3.3× higher kilocalorie per meter in SCI. Fuel partitioning was similar between groups and the same within groups for carbohydrate and fat oxidation. Nonsignificant (9%) lowering of the area under a glucose tolerance curve following bionic ambulation required 20% less insulin than at rest. CONCLUSION: Work intensity during prolonged bionic ambulation for this bionic exoskeleton is below a threshold for cardiorespiratory conditioning but above seated rest and passive standing. Bionic ambulation metabolism is consistent with low RPE and unchanged fuel partitioning from seated rest. Bionic ambulation did not promote beneficial effects on glycemia in well-conditioned, euglycemic participants. These findings may differ in less fit individuals with SCI or those with impaired glucose tolerance. Observed trends favoring this benefit suggest they are worthy of testing.

Oxytocin reduces adipose tissue inflammation in obese mice.

BACKGROUND: Obesity and adipose tissue expansion is characterized by a chronic state of systemic inflammation that contributes to disease. The neuropeptide, oxytocin, working through its receptor has been shown to attenuate inflammation in sepsis, wound healing, and cardiovascular disease. The current study examined the effects of chronic oxytocin infusions on adipose tissue inflammation in a murine model of obesity, the leptin receptor-deficient (db/db) mouse. METHODS: The effect of obesity on oxytocin receptor protein and mRNA expression in adipose tissue was evaluated by Western blotting and real-time polymerase chain reaction. Mice were implanted with osmotic minipumps filled with oxytocin or vehicle for 8 weeks. At study endpoint adipose tissue inflammation was assessed by measurement of cytokine and adipokine mRNA tissue levels, adipocyte size and macrophage infiltration via histopathology, and plasma levels of adiponectin and serum amyloid A as markers of systemic inflammation. RESULTS: The expression of adipose tissue oxytocin receptor was increased in obese db/db mice compared to lean controls. In adipose tissue oxytocin infusion reduced adipocyte size, macrophage infiltration, IL-6 and TNFα mRNA expression, and increased the expression of the anti-inflammatory adipokine, adiponectin. In plasma, oxytocin infusion reduced the level of serum amyloid A, a marker of systemic inflammation, and increased circulating adiponectin. CONCLUSIONS: In an animal model of obesity and diabetes chronic oxytocin treatment led to a reduction in visceral adipose tissue inflammation and plasma markers of systemic inflammation, which may play a role in disease progression.

Copper in Glucose Intolerance, Cognitive Decline, and Alzheimer Disease.

Trace metal dyshomeostasis has been linked to loss of cognitive performance. In particular, a disturbance in the regulation of copper (Cu), characterized by an increase in circulating Cu not bound to ceruloplasmin (non-Cp Cu), is thought to play a role in the development of Alzheimer disease (AD) and other neurodegenerative diseases in the aging population. Non-Cp Cu is redox active and its toxicity is thought to result from its ability to accelerate oxidative stress and advanced glycation endproduct (AGE) formation, leading to extracellular matrix damage in tissues including the brain. Cognitive loss is increasingly recognized to be a feature of type 2 diabetes and the increased AGE formation characteristic of diabetes may play a role in the development of this complication. There also is evidence for copper dyshomeostasis in type 2 diabetes, and therefore this could contribute to the cognitive deterioration associated with this disease. Demonstrating that disturbances of copper homeostasis correlate with an increased rate of cognitive decline in type 2 diabetes patients, and that they correlate with an increased rate of conversion from prediabetes to diabetes would bring almost immediate benefits in the clinical community in terms of treatment efficacy, AD prevention, and cost savings.

Hydroxypropyl-ß-cyclodextrin protects from kidney disease in experimental Alport syndrome and focal segmental glomerulosclerosis.

Studies suggest that altered renal lipid metabolism plays a role in the pathogenesis of diabetic kidney disease and that genetic or pharmacological induction of cholesterol efflux protects from the development of diabetic kidney disease and focal segmental glomerulosclerosis (FSGS). Here we tested whether altered lipid metabolism contributes to renal failure in the Col4a3 knockout mouse model for Alport Syndrome. There was an eight-fold increase in the cholesterol content in renal cortexes of mice with Alport Syndrome. This was associated with increased glomerular lipid droplets and cholesterol crystals. Treatment of mice with Alport Syndrome with hydroxypropyl-ß-cyclodextrin (HPßCD) reduced cholesterol content in the kidneys of mice with Alport Syndrome and protected from the development of albuminuria, renal failure, inflammation and tubulointerstitial fibrosis. Cholesterol efflux and trafficking-related genes were primarily affected in mice with Alport Syndrome and were differentially regulated in the kidney cortex and isolated glomeruli. HPßCD also protected from proteinuria and mesangial expansion in a second model of non-metabolic kidney disease, adriamycin-induced nephropathy. Consistent with our experimental findings, microarray analysis confirmed dysregulation of several lipid-related genes in glomeruli isolated from kidney biopsies of patients with primary FSGS enrolled in the NEPTUNE study. Thus, lipid dysmetabolism occurs in non-metabolic glomerular disorders such as Alport Syndrome and FSGS, and HPßCD improves renal function in experimental Alport Syndrome and FSGS.

A Shift in ApoM/S1P Between HDL-Particles in Women With Type 1 Diabetes Mellitus Is Associated With Impaired Anti-Inflammatory Effects of the ApoM/S1P Complex.

OBJECTIVE: Type 1 diabetes mellitus (T1D) patients have an increased risk of cardiovascular disease despite high levels of high-density lipoproteins (HDL). Apolipoprotein M (apoM) and its ligand sphingosine 1-phospate (S1P) exert many of the anti-inflammatory effects of HDL. We investigated whether apoM and S1P are altered in T1D and whether apoM and S1P are important for HDL functionality in T1D. APPROACH AND RESULTS: ApoM and S1P were quantified in plasma from 42 healthy controls and 89 T1D patients. HDL was isolated from plasma and separated into dense, medium-dense, and light HDL by ultracentrifugation. Primary human aortic endothelial cells were challenged with tumor necrosis factor-α in the presence or absence of isolated HDL. Proinflammatory adhesion molecules E-selectin and vascular cellular adhesion molecule-1 were quantified by flow cytometry. Activation of the S1P1- receptor was evaluated by analyzing downstream signaling targets and receptor internalization. There were no differences in plasma levels of apoM and S1P between controls and T1D patients, but the apoM/S1P complexes were shifted from dense to light HDL particles in T1D. ApoM/S1P in light HDL particles from women were less efficient in inhibiting expression of vascular cellular adhesion molecule-1 than apoM/S1P in denser particles. The light HDL particles were unable to activate Akt, whereas all HDL subfractions were equally efficient in activating Erk and receptor internalization. CONCLUSIONS: ApoM/S1P in light HDL particles were inefficient in inhibiting tumor necrosis factor-α-induced vascular cellular adhesion molecule-1 expression in contrast to apoM/S1P in denser HDL particles. T1D patients have a higher proportion of light particles and hence more dysfunctional HDL, which could contribute to the increased cardiovascular disease risk associated with T1D.

Comprehensive Metabolomics Study To Assess Longitudinal Biochemical Changes and Potential Early Biomarkers in Nonobese Diabetic Mice That Progress to Diabetes.

A global nontargeted longitudinal metabolomics study was carried out in male and female NOD mice to characterize the time-profile of the changes in the metabolic signature caused by onset of type 1 diabetes (T1D) and identify possible early biomarkers in T1D progressors. Metabolomics profiling of samples collected at five different time-points identified 676 and 706 biochemicals in blood and feces, respectively. Several metabolites were expressed at significantly different levels in progressors at all time-points, and their proportion increased strongly following onset of hyperglycemia. At the last time-point, when all progressors were diabetic, a large percentage of metabolites had significantly different levels: 57.8% in blood and 27.8% in feces. Metabolic pathways most strongly affected included the carbohydrate, lipid, branched-chain amino acid, and oxidative ones. Several biochemicals showed considerable (>4×) change. Maltose, 3-hydroxybutyric acid, and kojibiose increased, while 1,5-anhydroglucitol decreased more than 10-fold. At the earliest time-point (6-week), differences between the metabolic signatures of progressors and nonprogressors were relatively modest. Nevertheless, several compounds had significantly different levels and show promise as possible early T1D biomarkers. They include fatty acid phosphocholine derivatives from the phosphatidylcholine subpathway (elevated in both blood and feces) as well as serotonin, ribose, and arabinose (increased) in blood plus 13-HODE, tocopherol (increased), diaminopimelate, valerate, hydroxymethylpyrimidine, and dulcitol (decreased) in feces. A combined metabolic signature based on these compounds might serve as an early predictor of T1D-progressors.

Regulation of the macrophage oxytocin receptor in response to inflammation.

It has been demonstrated that the neuropeptide oxytocin (OT) attenuates oxidative stress and inflammation in macrophages. In the current study, we examined the role of inflammation on the expression of the oxytocin receptor (OXTR). We hypothesized that OXTR expression is increased during the inflammation through a nuclear factor-κB (NF-κB)-mediated pathway, thus responding as an acute-phase protein. Inflammation was induced by treating macrophages (human primary, THP-1, and murine) with lipopolysaccharide (LPS) and monitored by expression of IL-6. Expression of OXTR and vasopressin receptors was assessed by qPCR, and OXTR expression was confirmed by immunoblotting. Inflammation upregulated OXTR transcription 10- to 250-fold relative to control in THP-1 and human primary macrophages and increased OXTR protein expression. In contrast, vasopressin receptor-2 mRNA expression was reduced following LPS treatment. Blocking NF-κB activation prevented the increase in OXTR transcription. OT treatment of control cells and LPS-treated cells increased ERK1/2 phosphorylation, demonstrating activation of the OXTR/Gαq/11 signaling pathway. OT activation of OXTR reduced secretion of IL-6 in LPS-activated macrophages. Collectively, these findings suggest that OXTR is an acute-phase protein and that its increased expression is regulated by NF-κB and functions to attenuate cellular inflammatory responses in macrophages.

Structural Remodeling of Sympathetic Innervation in Atherosclerotic Blood Vessels: Role of Atherosclerotic Disease Progression and Chronic Social Stress.

OBJECTIVE: The sympathetic nervous system (SNS) can undergo dramatic structural plasticity in response to behavioral factors and/or the presence of disease, leading to SNS hyperinnervation of peripheral tissues. The SNS has been proposed as an important mediator between stressful behavior and the progression of atherosclerosis in the vasculature. The present study examined whether structural remodeling of the SNS occurs in the vasculature in a genetically hyperlipidemic animal model of atherosclerosis, the Watanabe heritable hyperlipidemic rabbit (WHHL; relative to normolipidemic New Zealand white rabbits [NZW]), and whether SNS plasticity is driven by the progression of disease and/or by stressful social behavior. METHODS: WHHL and NZW rabbits were assigned to an unstable or stable social environment for 4 months. Aortic atherosclerosis was assessed and SNS aortic innervation quantified using immunofluorescent microscopy. RESULTS: Numerous SNS varicosities were observed throughout the aorta in WHHLs and NZWs, extending into the vascular media and intima, an innervation pattern not previously reported. WHHLs exhibited significantly greater innervation than NZWs (F(1,41) = 55.3, p < .001), with extensive innervation of the atherosclerotic neointima. The innervation density was highly correlated with the extent of disease in the WHHLs (r(21) = 0.855, p < .001). Social environment did not influence innervation in NZWs (aortic arch: p = .078, thoracic aorta: p = .34) or WHHLs (arch: p = .97, thoracic: p = .61). CONCLUSIONS: The findings suggest that hyperinnervation is driven largely by the progression of disease rather than social environment. SNS innervation patterns observed in atherosclerotic human and mouse aortas were consistent with the rabbit, suggesting that SNS hyperinnervation of the diseased vessel wall is a general feature across mammalian species.

GLP-1 response to sequential mixed meals: influence of insulin resistance.

Previous work has shown that potentiation of insulin release is impaired in non-diabetic insulin resistance; we tested the hypothesis that this defect may be related to altered glucagon-like peptide-1 (GLP-1) release. On consecutive days, 82 non-diabetic individuals, classified as insulin sensitive (IS, n=41) or insulin resistant (IR, n=41) by the euglycaemic clamp, were given two sequential mixed meals with standard (75 g, LCD) or double (150 g, HCD) carbohydrate content. Plasma glucose, insulin, C-peptide, non-esterified fatty acids (NEFA) and GLP-1 concentrations were measured; ß-cell function (glucose sensitivity and potentiation) was resolved by mathematical modelling. Fasting GLP-1 levels were higher in IR than IS (by 15%, P=0.006), and reciprocally related to insulin sensitivity after adjustment for sex, age, fat mass, fasting glucose or insulin concentrations. Mean postprandial GLP-1 responses were tightly correlated with fasting GLP-1, were higher for the second than the first meal, and higher in IR than IS subjects but only with LCD. In contrast, incremental GLP-1 responses were higher during (i) the second than the first meal, (ii) on HCD than LCD, and (iii) significantly smaller in IR than IS independently of meal and load. Potentiation of insulin release was markedly reduced in IR vs IS across meal and carbohydrate loading. In the whole dataset, incremental GLP-1 was directly related to potentiation, and both were inversely related to mean NEFA concentrations. We conclude that (a) raised GLP-1 tone may be inherently linked with a reduced GLP-1 response and (b) defective post-meal GLP-1 response may be one mechanism for impaired potentiation of insulin release in insulin resistance.

Fibroblast Growth Factor 23 Is Associated With Subclinical Cerebrovascular Damage: The Northern Manhattan Study.

BACKGROUND AND PURPOSE: Elevated fibroblast growth factor 23 (FGF23) regulates phosphate homeostasis and is linked with mortality, cardiovascular events, and stroke. However, the role of FGF23 as a risk factor for subclinical cerebrovascular damage is unclear. METHODS: We used multivariable linear and logistic regression to evaluate associations between FGF23, continuously and by quartiles, with white matter hyperintensity volume, expressed as percent intracranial volume (%ICV), and subclinical brain infarction (SBI) in a community-based stroke-free sample. RESULTS: There were 1170 stroke-free Northern Manhattan Study (NOMAS) participants with FGF23 levels and quantitative magnetic resonance imaging data on white matter hyperintensity volume and SBI. Participants with FGF23 levels in the top quartile (range=85-1425 RU/mL) had greater white matter hyperintensity volume (ß=0.19 %ICV; 95% CI, 0.04-0.33 %ICV; P=0.01) compared with those in the lowest quartile (range=15-49 RU/mL), adjusted for demographics, vascular risk factors, and estimated glomerular filtration rate. These findings remained significant in those without evidence of chronic kidney disease (estimated glomerular filtration rate <60 mL/min per 1.73 m(2)). Elevated FGF23 was not associated with SBI overall after adjusting for demographic factors and estimated glomerular filtration rate, but sex modified the effect of FGF23 on odds of SBI (P for interaction=0.03). FGF23 was associated with significantly greater odds of SBI only in men (odds ratio, 1.7; 95% CI, 1.1-2.7; P=0.03) after full adjustment. CONCLUSIONS: These cross-sectional community-based data from a diverse urban sample show an association between elevated FGF23 and small vessel disease and magnetic resonance imaging-defined brain infarction in men, independent of chronic kidney disease. Data on elevated FGF23 and subclinical cerebrovascular damage progression are needed.

Effects of a Multicomponent Life-Style Intervention on Weight, Glycemic Control, Depressive Symptoms, and Renal Function in Low-Income, Minority Patients With Type 2 Diabetes: Results of the Community Approach to Lifestyle Modification for Diabetes Randomized Controlled Trial.

OBJECTIVE: Few interventions have combined life-style and psychosocial approaches in the context of Type 2 diabetes management. The purpose of this study was to determine the effect of a multicomponent behavioral intervention on weight, glycemic control, renal function, and depressive symptoms in a sample of overweight/obese adults with Type 2 diabetes and marked depressive symptoms. METHODS: A sample of 111 adults with Type 2 diabetes were randomly assigned to a 1-year intervention (n = 57) or usual care (n = 54) in a parallel groups design. Primary outcomes included weight, glycosylated hemoglobin, and Beck Depression Inventory II score. Estimated glomerular filtration rate served as a secondary outcome. All measures were assessed at baseline and 6 and 12 months after randomization by assessors blind to randomization. Latent growth modeling was used to examine intervention effects on each outcome. RESULTS: The intervention resulted in decreased weight (mean [M] = 0.322 kg, standard error [SE] = 0.124 kg, p = .010) and glycosylated hemoglobin (M = 0.066%, SE = 0.028%, p = .017), and Beck Depression Inventory II scores (M = 1.009, SE = 0.226, p < .001), and improved estimated glomerular filtration rate (M = 0.742 ml·min·1.73 m, SE = 0.318 ml·min·1.73 m, p = .020) each month during the first 6 months relative to usual care. CONCLUSIONS: Multicomponent behavioral interventions targeting weight loss and depressive symptoms as well as diet and physical activity are efficacious in the management of Type 2 diabetes. TRIAL REGISTRATION: This study is registered at Clinicaltrials.gov ID: NCT01739205.

Fibroblast Growth Factor 23 Is Associated With Carotid Plaque Presence and Area: The Northern Manhattan Study.

OBJECTIVE: Elevated fibroblast growth factor 23 (FGF23), a hormone that regulates phosphate homeostasis, has been associated with mortality, cardiovascular events, and stroke, and to arterial calcification in chronic kidney disease, but its role in atherosclerosis is unclear and population-based studies are lacking. We hypothesized that elevated FGF23 would associate with carotid plaque presence, area, and echogenicity in the race/ethnically diverse community-based Northern Manhattan Study (NOMAS) sample. APPROACH AND RESULTS: There were 1512 stroke-free NOMAS participants with FGF23 and 2-dimensional carotid ultrasound data (mean age, 68±9 years; 61% women; 62% Hispanic, 18% black, and 18% white). We used multivariable linear and logistic regression to evaluate FGF23, continuously and by quintiles, as a correlate of carotid plaque, plaque area (cubic root transformed), and echogenicity adjusting for sociodemographic and vascular risk factors. Participants with FGF23 levels in the top quintile were more likely to have carotid plaque (odds ratio, 1.49; 95% confidence interval, 1.02-2.19; P=0.04) and larger plaque area (ß=0.32 mm(2), 95% confidence interval, 0.10-0.53 mm(2); P=0.004) than those in the lowest quintile, adjusting for estimated glomerular filtration rate, demographics, and vascular risk factors. Linear regression models also showed that log transformed FGF23 (LnFGF23) associated with greater odds of plaque presence (odds ratio, 1.26 per LnFGF23; 95% confidence interval, 1.01-1.58; P=0.04), and plaque area (ß=0.19 mm(2) per LnFGF23; 95% confidence interval, 0.07-0.31 mm(2); P=0.002). CONCLUSIONS: Higher FGF23 associated with greater likelihood and burden of carotid atherosclerosis independent of CKD. Atherosclerosis may be a mechanism through which FGF23 increases cardiovascular events and stroke.

Cardiometabolic Syndrome in People With Spinal Cord Injury/Disease: Guideline-Derived and Nonguideline Risk Components in a Pooled Sample.

OBJECTIVE: To assess cardiometabolic syndrome (CMS) risk definitions in spinal cord injury/disease (SCI/D). DESIGN: Cross-sectional analysis of a pooled sample. SETTING: Two SCI/D academic medical and rehabilitation centers. PARTICIPANTS: Baseline data from subjects in 7 clinical studies were pooled; not all variables were collected in all studies; therefore, participant numbers varied from 119 to 389. The pooled sample included men (79%) and women (21%) with SCI/D >1 year at spinal cord levels spanning C3-T2 (American Spinal Injury Association Impairment Scale [AIS] grades A-D). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We computed the prevalence of CMS using the American Heart Association/National Heart, Lung, and Blood Institute guideline (CMS diagnosis as sum of risks ≥3 method) for the following risk components: overweight/obesity, insulin resistance, hypertension, and dyslipidemia. We compared this prevalence with the risk calculated from 2 routinely used nonguideline CMS risk assessments: (1) key cut scores identifying insulin resistance derived from the homeostatic model 2 (HOMA2) method or quantitative insulin sensitivity check index (QUICKI), and (2) a cardioendocrine risk ratio based on an inflammation (C-reactive protein [CRP])-adjusted total cholesterol/high-density lipoprotein cholesterol ratio. RESULTS: After adjustment for multiple comparisons, injury level and AIS grade were unrelated to CMS or risk factors. Of the participants, 13% and 32.1% had CMS when using the sum of risks or HOMA2/QUICKI model, respectively. Overweight/obesity and (pre)hypertension were highly prevalent (83% and 62.1%, respectively), with risk for overweight/obesity being significantly associated with CMS diagnosis (sum of risks, χ(2)=10.105; adjusted P=.008). Insulin resistance was significantly associated with CMS when using the HOMA2/QUICKI model (χ(2)2=21.23, adjusted P<.001). Of the subjects, 76.4% were at moderate to high risk from elevated CRP, which was significantly associated with CMS determination (both methods; sum of risks, χ(2)2=10.198; adjusted P=.048 and HOMA2/QUICKI, χ(2)2=10.532; adjusted P=.04). CONCLUSIONS: As expected, guideline-derived CMS risk factors were prevalent in individuals with SCI/D. Overweight/obesity, hypertension, and elevated CRP were common in SCI/D and, because they may compound risks associated with CMS, should be considered population-specific risk determinants. Heightened surveillance for risk, and adoption of healthy living recommendations specifically directed toward weight reduction, hypertension management, and inflammation control, should be incorporated as a priority for disease prevention and management.

Lifestyle modification and weight reduction among low-income patients with the metabolic syndrome: the CHARMS randomized controlled trial.

Although weight is an important intervention target among patients with metabolic syndrome, few trials have recruited low-income minority populations. The Community Health and Risk-reduction for Metabolic Syndrome randomized controlled trial aimed to examine the effects of a lifestyle intervention on weight and metabolic syndrome components among low-income minority adults. We randomized 120 adults with metabolic syndrome to standard medical care (N = 60) or a lifestyle intervention (N = 60). Using an intent-to-treat approach, we found significant intervention effects on weight [B = -0.452; SE = 0.122; 95 % confidence intervals (CI) -0.653 to -0.251) and glucose levels at 6-months (B = -0.522, SE = 0.234, 95 % CI -0.907 to -0.138). These changes were maintained through the 12-month assessment. No significant effects were observed on insulin resistance or other metabolic syndrome components. Our intervention was successful in achieving modest but significant weight loss and reduction in fasting glucose among low-income minority subjects with metabolic syndrome.

Effects of prandial challenge on triglyceridemia, glycemia, and pro-inflammatory activity in persons with chronic paraplegia.

CONTEXT/OBJECTIVE: Exaggerated postprandial lipemia has been reported after spinal cord injury (SCI). We examined metabolite and accompanying pro-inflammatory biomarker responses to repeat feeding of typical high-fat meals in individuals with chronic paraplegia. DESIGN: Descriptive trial. METHODS: Metabolites (triglycerides, glucose, and insulin) and inflammatory biomarkers (interleukin-6 and high-sensitivity C-reactive protein (hsCRP)) were measured under fasting conditions in 11 recreationally active individuals with chronic (>1 year) paraplegia. Subjects received high-fat meals at time point 0 and again at minute 240. Antecubital venous blood was obtained at time points -30 (fasting), 0 (first meal), 30, 60, 90, 120, 240 (second meal), 360, and 480 minutes. Correlations were examined among the study variables. Exploratory subgroup analysis was performed for subjects with levels of postprandial glucose greater than >200 mg/dl. RESULTS: Triglycerides showed a significant rise 4 hours after eating. Basal inflammatory markers were elevated, and did not undergo additional change during the testing. Additionally, subjects with excessive postprandial glucose responses showed higher hsCRP levels than those having typical glucose responses both for fasting (11.8 ± 6.5 vs. 2.9 ± 2.7 mg/l, P = 0.064) and postprandial (11.1 ± 4.9 vs. 3.7 ± 3.8 mg/l, P = 0.018) values. CONCLUSIONS: Despite elevations in metabolic response markers, inflammatory markers did not change significantly after consumption of population-representative (i.e. hypercaloric) mixed-nutrient meals. Levels of fasting CRP in the high-risk range are consistent with other reports in persons with SCI and continue to pose concern for their cardiovascular disease risk. The possible association between postprandial metabolic responses and inflammatory states warrants further investigation to identify individual component risks for this secondary health hazard.