Relationship between glycated hemoglobin and circulating 25-hydroxyvitamin D concentration in African American and Caucasian American men

Vitamin D deficiency associated with risk of prediabetes among older adults: Data from the National Health and Nutrition Examination Survey (NHANES), 2007-2012

AIM

To examine the association between vitamin D (25(OH)D) deficiency and risk of prediabetes in Americans 50+ years of age.

MATERIALS AND METHODS

This was a cross-sectional analysis of NHANES (2007-2012) subjects aged 50+ years, free of kidney/liver diseases and diabetes. Prediabetes was defined as: HbA1c level 5.7%-6.4%, or fasting plasma glucose level 100-125 mg/dL, or Oral Glucose Tolerance Test result 140-199 mg/dL, with no laboratory value in the diabetic range. The comparison group had normal glucose tolerance (NGT) with no marker in the prediabetes/diabetes range. Total serum 25(OH)D levels were deficient at <50 nmol/L, insufficient 50-75 nmol/L, and sufficient >75 nmol/L. Logistic regression included strata, cluster and weight variables. Models were adjusted for body mass index (BMI), ethnicity, age and gender.

RESULTS

The final sample was 2286 adults, predominantly White (80.4%) and female (56.6%), with a mean age of 62.3 years. Within the sample, 1387 had prediabetes (59.1%) and 899 were NGT (40.9%). Individuals classified within a lower serum vitamin D category were more likely to have prediabetes (p = 0.03). Those with 25(OH)D deficiency were more likely to have prediabetes compared to 25(OH)D sufficient individuals (crude OR = 1.48, 95% CI 1.15-1.91), and this association remained significant after adjustment for ethnicity, BMI, age and gender (aOR = 1.39, 95% CI 1.02-1.89). There was no effect modification by BMI, gender or ethnicity.

CONCLUSIONS

Vitamin D status was associated with risk of prediabetes in this sample of Americans 50+ years of age. Future research should seek to understand the potential mechanistic relationship between vitamin D and prediabetes.

Gender-Dependent Association of Vitamin D Deficiency with Obesity and Hypercholesterolemia (LDLC) in Adults

BACKGROUND

Obesity, dyslipidemia and vitamin D deficiency are growing health problems in the Arabian Gulf region. Their association with each other is yet to be clarified.

METHODS

Three-hundred and fourteen Bahraini adults, 164 males and 150 females comparable in median age (34.5 vs. 31.0 yrs), body mass index (BMI), and ethnicity were recruited. The plasma level of 25-hydroxyvitamin D3 (25OHD3) was measured by chemiluminescent immunoassay and lipid profile parameters were measured by an automated clinical chemistry analyzer. Based on BMI, study subjects were grouped into underweight, normal, overweight, moderate obesity, and severe obesity subjects.

RESULTS

The results revealed an extremely high prevalence of vitamin D deficiency (79.9%) and insufficiency (18.8%). The predictors of low 25OHD3 levels were female gender, small age, conservative dressing, least exposure to sunlight, and less fish intake. In all subjects, the lowest 25OHD3 level was seen in underweight and severe obesity groups. Furthermore, the 25OHD3 level was significantly higher in males as compared to females and it was positively correlated with the age. However, detailed analysis showed that overweight males unlike females had the highest 25OHD3 levels which were significantly higher than in the severely obese males. While the lipid profile parameters were positively correlated with BMI, the total and LDL cholesterols were negatively correlated with the levels of 25OHD3 in males.

CONCLUSION

Vitamin D deficiency was associated with both severely obese and underweight subjects, in the former it was likely to be institutional while in the latter it was likely to be nutritional. Furthermore, hypercholesterolemia (LDL-C) was associated with 25OHD3 sub-normality. Further analysis revealed that the significant associations were gender-dependent.

No Association between 25-Hydroxyvitamin D and Insulin Resistance or Thyroid Hormone Concentrations in a Romanian Observational Study

Background and objectives: Vitamin D is involved in insulin resistance through genomic and non-genomic mechanisms. Several observational and randomized studies have discrepant results; some of them showed an improved insulin resistance (IR), and others a neutral effect after vitamin D deficiency is corrected. Materials and Methods: We designed a retrospective observational study that included all women who presented for 33 months in an outpatient clinic in Bucharest, Romania. Results: We analyzed 353 patients with a mean age of 58.5 ± 13.7 years, a mean body mass index (BMI) of 27.36 ± 4.87 kg/m^-2, and a mean level of 25-hydroxyvitamin D (25OHD) of 39.53 ± 15.73 ng/mL. There were no differences in the calculated Homeostatic Model Assessment of Insulin Resistance variants 1 and 2 (HOMA-IR) and the Quantitative Insulin Sensitivity Check Index (QUICKI) between women with vitamin D deficit versus normal values. In multivariate analysis, there was no significant relation between 25OHD and the response variables considered by us. Conclusions: We observed a small positive correlation between a higher level of 25OHD and increased glycosylated hemolobin (HbA1c) or IR indices without clinical significance. Other modifiable or non-modifiable factors override 25OHD influence on IR in adult women with a normal serum level and may contribute to the remainder of the variability observed.

Directional Relationship Between Vitamin D Status and Prediabetes: A New Approach from Artificial Neural Network in a Cohort of Workers with Overweight-Obesity

Objective: Despite the increasing literature on the association of diabetes with inflammation, cardiovascular risk, and vitamin D (25(OH)D) concentrations, strong evidence on the direction of causality among these factors is still lacking. This gap could be addressed by means of artificial neural networks (ANN) analysis.Methods: Retrospective observational study was carried out by means of an innovative data mining analysis-known as auto-contractive map (AutoCM)-and semantic mapping followed by Activation and Competition System on data of workers referring to an occupational-health outpatient clinic. Parameters analyzed included weight, height, waist circumference, body mass index (BMI), percentage of fat mass, glucose, insulin, glycated hemoglobin (HbA1c), creatinine, total cholesterol, low- and high-density lipoprotein cholesterol, triglycerides, uric acid, fibrinogen, homocysteine, C-reactive protein (CRP), diastolic and systolic blood pressure, and 25(OH)D.Results: The study included 309 workers. Of these, 23.6% were overweight, 40.5% were classified into the first class of obesity, 23.3% were in the second class, and 12.6% were in the third class (BMI > 40 kg/m ). All mean biochemical values were in normal range, except for total cholesterol, low- and high-density lipoprotein cholesterol, CRP, and 25(OH)D. HbA1c was between 39 and 46 mmol/mol in 51.78%. 25(OH)D levels were sufficient in only 12.6%. Highest inverse correlation for hyperglycemia onset was with BMI and waist circumference, suggesting a protective role of 25(OH)D against their increase. AutoCM processing and the semantic map evidenced direct association of 25(OH)D with high link strength (0.99) to low CRP levels and low high-density lipoprotein cholesterol levels. Low 25(OH)D led to changes in glucose, which affected metabolic syndrome biomarkers, first of which was homeostatic model assessment index and blood glucose, but not 25(OH)D.Conclusions: The use of ANN suggests a key role of 25(OH)D respect to all considered metabolic parameters in the development of diabetes and evidences a causation between low 25(OH)D and high glucose concentrations.

Association of vitamin d with glycemic control in Saudi patients with type 2 diabetes: A retrospective chart review study in an emerging university hospital

Background

Vitamin D (mainly 25‐hydroxyvitamin D, 25[OH]D) has stimulated increasing interest in Saudi Arabia over the current years due to its association with several different chronic diseases such as diabetes. This study aims to ascertain whether the vitamin D level has any influence on glycemic control in Saudi patients with type 2 diabetes (T2DM).

Method

This retrospective study included 200 patients with T2DM who visited Prince Sattam Bin Abdulaziz University Hospital between January 2015 and December 2015. Venous blood was collected and examined for “serum/plasma levels of 25(OH)D” and related variables using kit methods. HbA1C levels <7% and ≥7% were taken as indicators of good and poor glycemic control, respectively. An association between vitamin D deficiency and poor glycemic control was determined using multinomial logistic regression analysis.

Results

Among the total of 200 patients with type 2 diabetes, 118 (59%) were female and 82 (41%) were males with the mean age 42.4 ± 14.8 years. Good glycemic control (HbA1c < 7) was observed in 127 (63.5%), and poor glycemic control (HbA1c > 7) was found in 73(36.5%). The mean serum 25(OH)vit D was 20.27 ± 8.66 ng/mL, with (52% vs 82%; P ≤ .001) of subjects identified to have vitamin D deficiency in good and poor glycemic control groups, respectively.

Conclusion

Taken together, our results demonstrated an association of vitamin D level with poor glycemic control in patients with type 2 diabetes. However, additional studies with larger sample size from local population are warranted in future to confirm and extend the findings of the present study.

Analysis of Association between Vitamin D Deficiency and Insulin Resistance

Recent evidence revealed extra skeleton activity of vitamin D, including prevention from cardiometabolic diseases and cancer development as well as anti-inflammatory properties. It is worth noting that vitamin D deficiency is very common and may be associated with the pathogenesis of insulin-resistance-related diseases, including obesity and diabetes. This review aims to provide molecular mechanisms showing how vitamin D deficiency may be involved in the insulin resistance formation. The PUBMED database and published reference lists were searched to find studies published between 1980 and 2019. It was identified that molecular action of vitamin D is involved in maintaining the normal resting levels of ROS and Ca2+, not only in pancreatic β-cells, but also in insulin responsive tissues. Both genomic and non-genomic action of vitamin D is directed towards insulin signaling. Thereby, vitamin D reduces the extent of pathologies associated with insulin resistance such as oxidative stress and inflammation. More recently, it was also shown that vitamin D prevents epigenetic alterations associated with insulin resistance and diabetes. In conclusion, vitamin D deficiency is one of the factors accelerating insulin resistance formation. The results of basic and clinical research support beneficial action of vitamin D in the reduction of insulin resistance and related pathologies.

Association between serum 25-hydroxyvitamin D and glycated hemoglobin levels in type 2 diabetes patients with chronic kidney disease

AIMS/INTRODUCTION

Vitamin D is suggested to influence glucose homeostasis. An inverse relationship between serum 25-hydroxyvitamin D (25[OH]D) and glycemic control in non-chronic kidney disease (CKD) patients with type 2 diabetes was reported. We aimed to examine this association among type 2 diabetes patients with CKD.

MATERIALS AND METHODS

A total of 100 type 2 diabetes participants with stage 3-4 CKD were recruited. Blood for glycated hemoglobin (HbA1c ), serum 25(OH)D, renal and lipid profiles were drawn at enrollment. Correlation and regression analyses were carried out to assess the relationship of serum 25(OH)D, HbA1c and other metabolic traits.

RESULTS

A total of 30, 42, and 28% of participants were in CKD stage 3a, 3b and 4, respectively. The proportions of participants based on ethnicity were 51% Malay, 24% Chinese and 25% Indian. The mean (±SD) age and body mass index were 60.5 ± 9.0 years and 28.3 ± 5.9 kg/m2 , whereas mean HbA1c and serum 25(OH)D were 7.9 ± 1.6% and 37.1 ± 22.2 nmol/L. HbA1c was negatively correlated with serum 25(OH)D (rs = -0.314, P = 0.002), but positively correlated with body mass index (rs = 0.272, P = 0.006) and serum low-density lipoprotein cholesterol (P = 0.006). There was a significant negative correlation between serum 25(OH)D and total daily dose of insulin prescribed (rs = -0.257, P = 0.042). Regression analyses showed that every 10-nmol/L decline in serum 25(OH)D was associated with a 0.2% increase in HbA1c .

CONCLUSIONS

Lower serum 25(OH)D was associated with poorer glycemic control and higher insulin use among multi-ethnic Asians with type 2 diabetes and stage 3-4 CKD.

Is Hypovitaminosis D Related to Incidence of Type 2 Diabetes and High Fasting Glucose Level in Healthy Subjects: A Systematic Review and Meta-Analysis of Observational Studies

There is evidence that vitamin D status is associated with type 2 diabetes. Many observational studies have been performed investigating the relationship of vitamin D status and circulating biomarkers of glycemic regulation. To find out whether this association holds, we conducted a systematic review and meta-analysis of cross sectional and longitudinal studies. We searched Pubmed, Medline and Embase, all through June 2017. The studies were selected to determine the effect of vitamin D on the parameters of glucose metabolism in diabetic and non-diabetic subjects. Correlation coefficients from all studies were pooled in a random effects meta-analysis. The risk of bias was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. We found significant inverse relationship of vitamin D status with glycemic level in both diabetic (r = -0.223, 95% CI = -0.184 to -0.261, p = 0.000) and non-diabetic (r = -0.073, 95% CI = -0.052 to -0.093, p = 0.000) subjects. This meta-analysis concludes that hypovitaminosis D is associated with increased risk of hyperglycemia both in diabetic and non-diabetic subjects. A future strategy for the prevention of impaired glycemic regulation could be individualized supplementation of vitamin D.

Body composition and metabolic profile in adults with vitamin D deficiency

ABSTRACT Objective: To investigate the body composition and metabolic profile in individuals in terms of different concentrations of serum vitamin D, ranging from deficiency to sufficiency. Methods: A cross-sectional study of 106 adults of both genders, who were divided into three groups according to vitamin D levels: deficiency: <20ng/mL; insufficiency: 20-29.9ng/mL; and sufficiency: 30-100ng/mL. Anthropometric evaluation included weight, height, and body circumferences. Fat mass and lean mass were assessed using the Tetrapolar bioelectrical impedance method. Clinical and biochemical evaluations were also carried out. Insulin resistance was estimated using the Homeostasis Model Assessment Insulin index. Results: The analysis showed that the main alterations in individuals in the vitamin D deficiency group were higher triglycerides, very low density lipoprotein - cholesterol, fasting blood glucose, insulin, glycated hemoglobin, body mass index, body fat percentage, lean mass percentage, waist circumference, and Homeostasis Model Assessment Insulin than those of the vitamin D sufficient group (p<0.05). Conclusion: It was found that vitamin D deficiency causes important body composition and metabolic changes, which may lead to diseases such as diabetes Mellitus and metabolic syndrome.

The Association of Serum 25-Hydroxyvitamin D Concentrations and Elevated Glycated Hemoglobin Values: A Longitudinal Study of Non-Diabetic Participants of a Preventive Health Program

The prevalence of Type 2 Diabetes (T2D) is sharply on the rise, both in Canada and worldwide. As addressing its root causes, i.e., promotion of healthy lifestyles and weight management, has been largely unsuccessful, new clues for primary prevention seem essential to curbing the increasing public health burden of T2D. In the present study, we examined whether improvements in vitamin D status, i.e., serum 25-hydroxyvitamin D [25(OH)D] concentrations, are paralleled by a reduction in the risk for reaching adverse glycated hemoglobin (HbA_1c) levels in a community sample of non-diabetic volunteers participating in a preventive health program that encourages the use of vitamin D. Repeated observations on 6565 participants revealed that serum 25(OH)D concentrations increased from 90.8 to 121.3 nmol/L, HbA_1c values decreased from 5.6% to 5.5%, and the prevalence of having HbA_1c values ≥ 5.8% decreased from 29.5% to 17.4% while in the program. Compared to participants who did not increase their 25(OH)D concentrations during follow-up, those who increased their 25(OH)D concentrations with 50 nmol/L or more were 0.74 times as likely to achieve elevated HbA_1c values at follow-up (p = 0.03). These findings suggest that public health initiatives that promote vitamin D status along with healthy lifestyles in the population at large may alleviate the future public health burden associated with T2D.

Vitamin D status is inversely associated with markers of risk for type 2 diabetes: A population based study in Victoria, Australia

A growing body of evidence suggests a protective role of vitamin D on the risk of type 2 diabetes mellitus (T2DM). We investigated this relationship in a population sample from one Australian state. The data of 3,393 Australian adults aged 18-75 years who participated in the 2009-2010 Victorian Health Monitor survey was analyzed. Socio-demographic information, biomedical variables, and dietary intakes were collected and fasting blood samples were analyzed for 25, hydroxycholecalciferol (25OHD), HbA1c, fasting plasma glucose (FPG), and lipid profiles. Logistic regression analyses were used to evaluate the association between tertiles of serum 25OHD and categories of FPG (<5.6 mmol/L vs. 5.6-6.9 mmol/L), and HbA1c (<5.7% vs. 5.7-6.4%). After adjusting for social, dietary, biomedical and metabolic syndrome (MetS) components (waist circumference, HDL cholesterol, triglycerides, and blood pressure), every 10 nmol/L increment in serum 25OHD significantly reduced the adjusted odds ratio (AOR) of a higher FPG [AOR 0.91, (0.86, 0.97); p = 0.002] and a higher HbA1c [AOR 0.94, (0.90, 0.98); p = 0.009]. Analysis by tertiles of 25OHD indicated that after adjustment for socio-demographic and dietary variables, those with high 25OHD (65-204 nmol/L) had reduced odds of a higher FPG [AOR 0.60, (0.43, 0.83); p = 0.008] as well as higher HbA1c [AOR 0.67, (0.53, 0.85); p = 0.005] compared to the lowest 25OHD (10-44 nmol/L) tertile. On final adjustment for other components of MetS, those in the highest tertile of 25OHD had significantly reduced odds of higher FPG [AOR 0.61, (0.44, 0.84); p = 0.011] and of higher HbA1c [AOR 0.74, (0.58, 0.93); p = 0.041] vs. low 25OHD tertile. Overall, the data support a direct, protective effect of higher 25OHD on FPG and HbA1c; two criteria for assessment of risk of T2DM.

Vitamin D, sub-inflammation and insulin resistance. A window on a potential role for the interaction between bone and glucose metabolism

Vitamin D is a key hormone involved in the regulation of calcium/phosphorous balance and recently it has been implicated in the pathogenesis of sub-inflammation, insulin resistance and obesity. The two main forms of vitamin D are cholecalciferol (Vitamin D3) and ergocalciferol (Vitamin D2): the active form (1,25-dihydroxyvitamin D) is the result of two hydroxylations that take place in liver, kidney, pancreas and immune cells. Vitamin D increases the production of some anti-inflammatory cytokines and reduces the release of some pro-inflammatory cytokines. Low levels of Vitamin D are also associated with an up-regulation of TLRs expression and a pro-inflammatory state. Regardless of the effect on inflammation, Vitamin D seems to directly increase insulin sensitivity and secretion, through different mechanisms. Considering the importance of low grade chronic inflammation in metabolic syndrome, obesity and diabetes, many authors hypothesized the involvement of this nutrient/hormone in the pathogenesis of these diseases. Vitamin D status could alter the balance between pro and anti-inflammatory cytokines and thus affect insulin action, lipid metabolism and adipose tissue function and structure. Numerous studies have shown that Vitamin D concentrations are inversely associated with pro-inflammatory markers, insulin resistance, glucose intolerance and obesity. Interestingly, some longitudinal trials suggested also an inverse association between vitamin D status and incident type 2 diabetes mellitus. However, vitamin D supplementation in humans showed controversial effects: with some studies demonstrating improvements in insulin sensitivity, glucose and lipid metabolism while others showing no beneficial effect on glycemic control and on inflammation. In conclusion, although the evidences of a significant role of Vitamin D on inflammation, insulin resistance and insulin secretion in the pathogenesis of obesity, metabolic syndrome and type 2 diabetes, its potential function in treatment and prevention of type 2 diabetes mellitus is unclear. Encouraging results have emerged from Vitamin D supplementation trials on patients at risk of developing diabetes and further studies are needed to fully explore and understand its clinical applications.

Risk factors and predictors of uncontrolled hyperglycemia and diabetic ketoacidosis in children and adolescents with type 1 diabetes mellitus in Jeddah, western Saudi Arabia

BACKGROUND

Little is known about levels of glycemic control and risk factors for uncontrolled hyperglycemia in Saudi children with type 1 diabetes mellitus (T1DM). The aim of the present study was to identify levels of glycemic control, risk factors and predictors of uncontrolled hyperglycemia (HG) and diabetic ketoacidosis (DKA) in children with T1DM.

METHODS

A retrospective study was performed on Saudi children and adolescents with confirmed T1DM who were followed at the Pediatric Endocrinology Clinic of the Maternity and Children Hospital, Jeddah, from 2000 to 2014. Data collection included all possible factors that may be associated with uncontrolled T1DM. Patients were classified according to American Diabetes Association guidelines for target HbA1c levels per age group. Comparisons were made between well-controlled (WC) patients, HG patients, and DKA patients. Calculation of odds ratios and logistic regression allowed for estimation of the role of each risk factor in uncontrolled T1DM.

RESULTS

Only 31.2 % of children and adolescents with T1DM were well controlled. Better glycemic control was associated with age < 6 years, urban residence, and T1DM duration <5 years. Glycemic control was not affected by gender, insulin therapy, or comorbidities. The most significant independent predictors of hyperglycemia and DKA were poor compliance with a healthy lifestyle (adjusted hazards ratio [AHR] 28.94; 95 % confidence interval [CI] 8.37-100.04) and an excess intake of sweets (AHR 3.31; 95 % CI 1.54-7.11).

CONCLUSION

The most significant independent predictor for poor glycemic control (particularly DKA rather than hyperglycemia) in Saudi children and adolescents was poor compliance with a healthy lifestyle with an excessive intake of sweets.

Associations of 25-hydroxyvitamin D with markers of inflammation, insulin resistance and obesity in black and white community-dwelling adults

AIMS

Vitamin D is a fat-soluble vitamin classically known for its role in calcium absorption and bone health. Growing evidence indicates that vitamin D deficiency may be associated with inflammation, insulin resistance, and obesity. However, prior studies examining the association of vitamin D with metabolic risk factors had relatively low representation of individuals of black race, limiting their ability to characterize associations of vitamin D and parameters of metabolic health in black vs. white individuals.

METHODS

We examined associations of 25-hydroxyvitamin D (25(OH)D) concentrations with markers of inflammation (interleukin [IL]-6, IL-10, high sensitivity C-reactive protein [hsCRP]), insulin sensitivity (adiponectin, resistin, HOMA-IR), and obesity (body mass index [BMI], waist circumference) in 1,042 participants from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a large national cohort of black and white adults 45 years or older.

RESULTS

In unadjusted analyses, lower 25(OH)D concentrations were associated with higher IL-6 and hsCRP concentrations; lower adiponectin concentrations; higher HOMA-IR; and higher BMI and waist circumference (P<0.05 for all). After adjustment for sociodemographic, clinical, lifestyle, and laboratory variables, lower 25(OH) D concentrations remained associated with lower adiponectin concentrations, higher IL-6 concentrations, higher HOMA-IR, and higher BMI and waist circumference (P <0.05 for all). The magnitude of these associations did not differ by race (P_interaction>0.1).

CONCLUSIONS

Lower 25(OH)D concentrations are associated with disturbances in metabolic health in both blacks and whites. Whether correcting vitamin D deficiency could offer a beneficial therapy for additional disease prevention requires further study.

Racial and Economic Disparities in Diabetes in a Large Primary Care Patient Population

OBJECTIVE

We sought to determine if, after adjusting for economic status, race is an independent risk factor for glycemic control among diabetic patients in a large primary care patient population.

DESIGN SETTING PARTICIPANTS

We performed a retrospective chart review of 264,000 primary care patients at our large, urban academic medical center to identify patients with a diagnosis of diabetes (n=25,123). Zip code was used to derive median income levels using US Census Bureau demographic information. Self-reported race was extracted from registration data.

MAIN OUTCOME MEASURES

The prevalence of diabetes, average glycated hemoglobin (A1c), and prevalence of uncontrolled diabetes of White and Black patients at all income levels were determined.

RESULTS

White patients had a lower average A1c level and a lower prevalence of diabetes than Black patients in all income quartiles (P<.001). Among White patients, the prevalence of diabetes (P<.001), uncontrolled diabetes (P<.001), and A1c level (P=.014) were inversely proportional to income level. No significant difference in the prevalence of diabetes (P=.214), A1c level (P=.282), or uncontrolled diabetes related to income was seen in Black patients (P=.094).

CONCLUSIONS

Race had an independent association with diabetes prevalence and glycemic control. Our study does not support two prominent theories that economic and insurance status are the main factors in diabetes disparities, as we attempted to control for economic status and nearly every patient had insurance. It will be important for future analysis to explore how health care system factors affect these observed gaps in quality.

Relationship between vitamin D status, glycemic control and cardiovascular risk factors in Brazilians with type 2 diabetes mellitus

OBJECTIVES

Determine the prevalence and identify predictors of hypovitaminosis D in patients with type 2 diabetes mellitus (T2DM); 2) correlate vitamin D levels with variables indicative of glycemic control and cardiovascular risk.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional study with consecutive patients treated at a University Hospital's Endocrinology outpatient clinic located at 12°58'S latitude, between October 2012 and November 2013. Hypovitaminosis D was defined as 25-hydroxyvitamin D < 30 ng/mL (chemiluminescence).

RESULTS

We evaluated 108 patients with mean duration of T2DM of 14.34 ± 8.05 years and HbA1c of 9.2 ± 2.1%. Mean age was 58.29 ± 10.34 years. Most were women (72.2%), non-white (89.8%) and had hypertension (75.9%) and dyslipidemia (76.8%). Mean BMI was 28.01 ± 4.64 kg/m²; 75.9% were overweight. The prevalence of hypovitaminosis D was 62%. In multiple logistic regression, independent predictors of hypovitaminosis D were female gender (OR 3.10, p = 0.02), dyslipidemia (OR 6.50, p < 0.01) and obesity (OR 2.55, p = 0.07). In multiple linear regression, only total cholesterol (β = -0.36, p < 0.01) and BMI (β = -0.21, p = 0.04) remained associated with levels of 25-hydroxyvitamin D.

CONCLUSIONS

Using currently recommended cutoffs, the prevalence of hypovitaminosis D in Brazilians with T2DM was as high as that of non-tropical regions. Female gender, dyslipidemia and obesity were predictors of hypovitaminosis D. Low levels of 25-hydroxyvitamin D were correlated with high cholesterol and BMI values. Future studies are needed to evaluate whether vitamin D replacement would improve these parameters and reduce hard cardiovascular outcomes.

Vitamin D Attenuates Left Atrial Volume Changes in African American Males with Obesity and Prediabetes

Vitamin D deficiency is common among African Americans in the United States and is associated with increased cardiovascular disease risk. In this study, prediabetic African American males who were found to be vitamin D-deficient were randomized to vitamin D supplementation and assessed for changes in left atrial (LA) volume. Prediabetic African American males who were vitamin D-deficient (25(OH)D: 5.0-29 ng/mL) were randomized to high-dose ergocalciferol or placebo. Echocardiography was performed at baseline and at 1 year. Ejection fraction (EF), septal and posterior wall thickness, LA area, LA length, LA volume, E, A, septal and lateral e' and a', deceleration time, and isovolumetric relaxation time were collected. Eighty-one of 158 (51%) subjects received vitamin D2 . Baseline characteristics were similar among both groups. In the placebo group, left atrial volume significantly increased on follow-up (LA volume increased 6.3 mL, P = 0.0025). Compared with placebo group, the treatment group with ergocalciferol had attenuated increases in left atrial volume (LA volume increased 2.6 mL, P = 0.29). Changes in left atrial volume persisted when indexed to body surface area. There was no significant difference in other diastolic parameters and blood pressure between groups. In conclusion, vitamin D-deficient prediabetic African American males who were treated with high-dose vitamin D2 were found to have attenuated increases in left atrial volume compared with controls over 12-month follow-up.

Common biological mechanisms between bipolar disorder and type 2 diabetes: Focus on inflammation

INTRODUCTION

Bipolar disorder (BD) patients present a 3-5 fold greater risk of developing type 2 diabetes (T2D) compared to general population. The underlying mechanisms for the increased prevalence of T2D in BD population are poorly understood.

OBJECTIVES

The purpose of this review is to critically review evidence suggesting that inflammation may have an important role in the development of both BD and T2D.

RESULTS

The literature covered in this review suggests that inflammatory dysregulation take place among many BD patients. Such dysregulated and low grade chronic inflammatory process may also increase the prevalence of T2D in BD population. Current evidence supports the hypothesis of dysregulated inflammatory processes as a critical upstream event in BD as well as in T2D.

CONCLUSIONS

Inflammation may be a factor for the development of T2D in BD population. The identification of inflammatory markers common to these two medical conditions will enable researchers and clinicians to better understand the etiology of BD and develop treatments that simultaneously target all aspects of this multi-system condition.

Correlations between serum levels of 25-hydroxyvitamin D and carotid atherosclerosis in patients with type 2 diabetes in Shanghai

OBJECTIVE

To explore the potential association between the serum levels of 25-hydroxyvitamin D [25(OH)D] and carotid atherosclerosis in patients with type 2 diabetes.

MATERIAL AND METHODS

Three hundred and fifty patients with type 2 diabetes were enrolled in this study in Shanghai, China. B-mode ultrasound was used to detect carotid plaques as indicators of atherosclerosis and measure carotid artery intima-media wall thickness (C-IMT) at two sites of carotid artery. Subjects were divided into group A (patients with carotid plaques) and group B (patients without carotid plaques) and be assessed clinically. Serum levels of 25(OH)D and other clinical parameters were measured. Multivariate logistic regression was performed to find predictors of carotid atherosclerosis in the entire group.

RESULTS

The levels of serum 25(OH)D were lower in group A than in group B[19.60 (13.30-25.73) vs 23.19 (18.10-30.06)ng/ml, P<0.001]. The C-IMT levels [(1.00±0.17 vs 0.88±0.20)mm, Ptrend<0.001] and proportion of people with carotid plaques(44/88 vs 20/87, Ptrend<0.001) in the lowest quartile of 25(OH)D were higher than in the highest quartile. Vitamin D concentrations were inversely associated with HbA1c in women(r=-0.194, P=0.006), and C-IMT in men(r=-0.409, P<0.001). Logistic regression analysis showed age, male sex, current smoke, history of hypertension, SBP, LDL-C and lg[25(OH)D] (OR: 0.924, 95%CI: 0.893-0.955, P<0.001) were independently associated with the presence of carotid plaques in T2DM.

CONCLUSIONS

Serum vitamin D level is significantly and independently associated with carotid atherosclerosis in patients with T2DM in Shanghai, China.