Association Between Vitamin D and Inflammation and Diabetes Risk in Morbidly Obese Pre-Menopausal Women (VitD2014)

Vitamin D, Inflammation, and Relations to Insulin Resistance in Morbidly Obese Pre-Menopausal Women

Obesity is associated with low-grade inflammation, insulin resistance and low vitamin D status. Vitamin D has traditionally been known to involve in calcium homeostasis and prevent rickets; however, recently it has been recognized to inversely associate with many non-skeletal diseases and conditions including obesity and type 2 diabetes (T2DM). In vitro studies have demonstrated that vitamin D possesses anti-inflammatory properties. It remains unknown if the effect of vitamin D on insulin sensitivity is mediated by suppressing inflammation in human adipose tissues. The main objective of this study was to assess the association between vitamin D and insulin sensitivity and inflammation in morbidly obese pre-menopausal women. Obese women (n=76) were recruited from the University of Illinois at Chicago (UIC) Nutrition and Wellness Center and the UIC medical center bariatric surgery clinics. Insulin sensitivity/resistance was assessed by (1) Oral glucose insulin sensitivity (OGIS) index, derived from dynamic oral glucose tolerance test (OGTT), and (2) Homeostasis model of insulin resistance (HOMA-IR), calculated from fasting steady-state glucose and insulin. Also, to better understand the potential mechanism and the role circulating vitamin D (25OHD) plays in adipose tissue inflammation, we assessed messenger ribonucleic acid (mRNA) expression of vitamin D receptor (VDR) and various inflammatory genes in visceral (VAT) and subcutaneous adipose tissues (SAT) of obese women that underwent a restrictive bariatric procedure. We hypothesized that subjects with higher serum vitamin D levels would be less inflamed and more insulin sensitive and have increased expression of VDR and pro-inflammatory markers compared to those with lower serum vitamin D levels.

Study Overview

• Status: Completed
• Conditions: Insulin Sensitivity

• Study Type: Observational
• Enrollment (Actual): 76

Contacts and Locations

Study Locations

• United States
  • Illinois
    • Chicago, Illinois, United States, 60612
      • University of Illinois at Chicago

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 49 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

Study subjects are drawn from women seeking surgical treatment for their morbid obesity at the University of Illinois at Chicago Medical Center (UICMC) Bariatric surgery clinics.

Description

Inclusion Criteria:

• Premenopausal women between the age of 21 and 49 years old
• BMI >=35(kg/m2)
• Not pregnant
• English speaking
• Approved for a bariatric surgery

Exclusion Criteria:

Subjects with:

• Diabetes
• Cancer
• Kidney disease
• Liver disease
• Gallbladder disease
• Rheumatoid arthritis
• HIV/AIDS
• Crohn's disease or inflammatory bowel disease
• Subjects taking anti-inflammatory medications

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
No intervention; There is no intervention to subjects in this study. All subjects are morbidly women seeking bariatric surgeries.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oral Glucose Insulin Sensitivity (OGIS)	Insulin sensitivity is assessed based with a 2-hour, 75gm Oral Glucose Tolerance Test. Blood samples are collected at 0, 90, and 120 min for the measurement of glucose and insulin.	2 hour, 1-5 weeks before bariatric surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adipose tissue mRNA Expression of Vitamin D Receptors and Inflammation Markers		10-20 minutes, during bariatric surgery
Inflammatory markers in plasma	Fasting blood drawn on Oral Glucose Tolerance Test day, which is 1-5 weeks before bariatric surgeries	3-15 minutes, 1-5 weeks before bariatric surgery

Collaborators and Investigators

• Sponsor: University of Illinois at Chicago
• Investigators: Principal Investigator: Carol Braunschweig, PhD, University of Illinois at Chicago

Study record dates

Study Major Dates

• Study Start: May 1, 2011
• Primary Completion (Actual): February 1, 2013
• Study Completion (Actual): February 1, 2013

Study Registration Dates

• First Submitted: June 18, 2014
• First Submitted That Met QC Criteria: June 18, 2014
• First Posted (Estimate): June 20, 2014

Study Record Updates

• Last Update Posted (Actual): February 5, 2020
• Last Update Submitted That Met QC Criteria: January 30, 2020
• Last Verified: January 1, 2020

More Information

Terms related to this study

• Keywords: Inflammation; Obesity; Vitamin D deficiency
• Additional Relevant MeSH Terms: Pathologic Processes; Glucose Metabolism Disorders; Metabolic Diseases; Hyperinsulinism; Inflammation; Insulin Resistance
• Other Study ID Numbers: 2010-1010