1. THE INFLUENCE OF REGIONAL ADIPOSITY
ON THE RELATIONSHIP BETWEEN
25(OH)D AND INSULIN SENSITIVITY
Wright CS,1 Weinheimer-Haus EM1, Fleet JC1,
Peacock M2, Campbell WW1
1Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
2Department of Medicine, Indiana University, Indianapolis, IN, USA

2. Vitamin D
• Wide spread vitamin D insufficiency
• 2/3rd of all Americans have low 25(OH)D
• Glucose homeostasis
• 2003-2004 NHANES: 25(OH)D (-) HOMA-IR
• Framingham Heart Study: 25(OH)D (-) fasting insulin
• Hyperglycemic euglycemic: 25(OH)D (-) fasting glucose, (+) ISI
• VD = Insulin Resistance & Diabetes
Ginde AA et al, Arch Intern Med, 2009; Lips P, Endocrin Rev, 2001
Wacker M, Nutrients, 2013; Reis JP et al, Eur J Endo, 2008
Cheng S et al, Diabetes, 2010; Lee DM et al, Eur J Endo, 2009

3. Increased Adiposity  Lower 25(OH)D
• BMI & Vitamin D
• Overweight (24%) and Obese (55%) less likely to be VD sufficient
• ‘13 Sys & Meta (n=34)  25(OH)D (-) BMI
• Central adiposity is a strong predictor of VD status
• Visceral fat (VAT) independently assoc. 25(OH)D
• VAT negatively associated with glucose tolerance
• Higher VAT increasing the risk of insulin resistance and diabetes
• VAT = VD & Insulin Resistance & Diabetes
Samuel et al, Ann Epidemiol, 2013; Saneei P et al, Obes Revs, 2013
Hao Y et al, Plos One, 2014; Yamashita S et al, Diabetes Care, 1996
Vague J, Am J Clin Nutr, 1956; Carr BR et al, Diabetes, 2002
Boyko EJ et al, Diabetes Care, 2000; Hayashi T et al, Diabetes Care, 2003

4. Is There a Connection?
Regional
Adiposity
Low Vitamin
D Status
Insulin
Resistance
?
? ?

5. Is Adiposity the Driving Force Behind
the Apparent Relationship Between
25(OH)D and Insulin Resistance?
• BMI-adjusted & Waist circumference-adjusted
• VD & insulin resistance relationship persists
• Attenuated or lost
• Influence of regional adiposity?
• Will the VD & insulin resistance relationship persist?

6. Objective & Aims
To assess the influence of regional adiposity on the
relationship between 25(OH)D and insulin resistance.
1. Total fat mass or regional adiposity which predicts VD?
• Adiposity & VD: Central adiposity predicts 25(OH)D
2. What are the independent effects of regional adiposity
and 25(OH)D on glucose and insulin markers?
• Adiposity & VD: (+) insulin resistance
3. How does adjusting for regional adiposity or 25(OH)D
affect their relationship to insulin and glucose markers?
• Adjusting for central adiposity - significance lost between 25(OH)D and markers
• Adjusting for 25(OH)D - significance unchanged

7. Methods
• Original Study
• Baseline data was used from a double-blind, placebo-controlled,
community-based, randomized 36-week intent-to-treat study
• N=336, age: 48.3 ± 7.7 y, Overweight and obese adults
• Body Composition
• DXA (LUNAR iDXA)
• Peripheral (appendicular & gynoid) and central (android) adiposity
• Blood Analysis
• 12-h overnight fasting blood samples, followed by OGTT
• Radioimmunoassay 25(OH)D
• Statistical Analysis (MLR)
• Model 1 - age, sex, and race
• Model 2 – age, sex, race, and 25(OH)D
• Model 3 – age, sex, race, and android FMI

8. Baseline Characteristics (n=336)
Adiposity Measures Mean (±SD) Mean (±SD)
BMI 30.4 (2.8) Gynoid Fat Mass (kg) 6.4 (1.5)
Total Fat Mass (kg) 35.5 (6.3) Gynoid Body Fat % 47.1 (9.6)
Total FMI 12.4 (2.5) Gynoid FMI 2.3 (0.6)
Total Body Fat % 40.8 (6.4)
Appendicular Fat Mass (kg) 38.5 (9.5) Android Fat Mass (kg) 3.6 (0.9)
Appendicular Body Fat % 11.4 (3.0) Android Body Fat % 52.2 (6.4)
Appendicular FMI 38.7 (8.9) Android FMI 1.3 (0.3)
Glucose Measures Vitamin D
Fasting Glucose (mg/dL) 95.3 (9.6) 25(OH)D (ng/ml) 24.0 (7.5)
Fasting Insulin (μIU/ml) 11.3 (6.1)
2hr-Glucose (mg/dL) 121.3 (35.3) S. Insuff 8.1-15 ng/ml 8.6%
2hr-Insulin (μIU/ml) 74.5 (65.1) M. Insuff 15.1-20 ng/ml 20.8%
Glucose AUC (mg/dL)*min 22532.3 (4518.6) Sufficiency 20.1-30 ng/ml 52.1%
Insulin AUC (μIU/ml)*min 12254.3 (7818.7) >30.1 ng/ml 18.5%
HOMA-IR 2.8 (1.8)
ISI 5.0 (3.1)

9. Total Fat Mass or Regional Adiposity?
• Measurements of adiposity were negatively associated with
VD after controlling for age, sex, and race
• Generalized adiposity
• BMI (Beta: -0.122, p-value=0.027)
• Total FMI (Beta: -0.161, p-value=0.018)
• Regional adiposity
• Android FMI (Beta: -0.113, p-value=0.042)

10. Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg) 0.179 0.001 0.321 <0.001 0.328 <0.001 -0.353 <0.001
Android Body Fat % 0.100 0.099 0.181 0.003 0.184 0.002 -0.317 <0.001
Android FMI 0.170 0.002 0.315 <0.001 0.312 <0.001 -0.373 <0.001
Peripheral Adiposity
Appendic. Fat Mass (kg) -0.052 0.457 0.014 0.845 0.041 0.563 0.079 0.258
Appendic. FMI -0.102 0.244 0.011 0.900 0.022 0.801 0.068 0.438
Gynoid Fat Mass (kg) -0.050 0.465 0.003 0.970 0.030 0.661 0.049 0.470
Gynoid Body Fat % -0.292 0.010 -0.303 0.008 -0.279 0.015 0.221 0.053
Gynoid FMI -0.096 0.261 -0.003 0.974 0.010 0.910 0.024 0.781
Regional Adiposity On Glucose and Insulin?
Model 1: Controlling for Age, Sex, and Race * Comparable results for AUC and 2hr markers
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg)
Android Body Fat %
Android FMI
Peripheral Adiposity
Appendic. Fat Mass (kg)
Appendic. FMI
Gynoid Fat Mass (kg)
Gynoid Body Fat %
Gynoid FMI

11. Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg) 0.179 0.001 0.321 <0.001 0.328 <0.001 -0.353 <0.001
Android Body Fat % 0.100 0.099 0.181 0.003 0.184 0.002 -0.317 <0.001
Android FMI 0.170 0.002 0.315 <0.001 0.312 <0.001 -0.373 <0.001
Peripheral Adiposity
Appendic. Fat Mass (kg) -0.052 0.457 0.014 0.845 0.041 0.563 0.079 0.258
Appendic. FMI -0.102 0.244 0.011 0.900 0.022 0.801 0.068 0.438
Gynoid Fat Mass (kg) -0.050 0.465 0.003 0.970 0.030 0.661 0.049 0.470
Gynoid Body Fat % -0.292 0.010 -0.303 0.008 -0.279 0.015 0.221 0.053
Gynoid FMI -0.096 0.261 -0.003 0.974 0.010 0.910 0.024 0.781
Regional Adiposity On Glucose and Insulin?
Model 1: Controlling for Age, Sex, and Race * Comparable results for AUC and 2hr markers

12. Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg)* 0.179 0.001 0.321 <0.001 0.328 <0.001 -0.353 <0.001
Android Body Fat % 0.100 0.099 0.181 0.003 0.184 0.002 -0.317 <0.001
Android FMI* 0.170 0.002 0.315 <0.001 0.312 <0.001 -0.373 <0.001
25(OH)D
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg)* 0.175 0.002 0.313 <0.001 0.323 <0.001 -0.352 <0.001
Android Body Fat % 0.093 0.128 0.169 0.005 0.176 0.004 -0.315 <0.001
Android FMI* 0.164 0.003 0.305 <0.001 0.306 <0.001 -0.371 <0.001
Is Significance Effected by Vitamin D Status?
Model 2: Controlling for Age, Sex, Race, and 25(OH)D
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg)*
Android Body Fat %
Android FMI*
25(OH)D
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg)*
Android Body Fat %
Android FMI*
Model 1: Controlling for Age, Sex, and Race
* Comparable results for AUC and 2hr markers

13. Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg)* 0.179 0.001 0.321 <0.001 0.328 <0.001 -0.353 <0.001
Android Body Fat % 0.100 0.099 0.181 0.003 0.184 0.002 -0.317 <0.001
Android FMI* 0.170 0.002 0.315 <0.001 0.312 <0.001 -0.373 <0.001
25(OH)D
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg)* 0.175 0.002 0.313 <0.001 0.323 <0.001 -0.352 <0.001
Android Body Fat % 0.093 0.128 0.169 0.005 0.176 0.004 -0.315 <0.001
Android FMI* 0.164 0.003 0.305 <0.001 0.306 <0.001 -0.371 <0.001
Is Significance Effected by Vitamin D Status?
Model 2: Controlling for Age, Sex, Race, and 25(OH)D
Model 1: Controlling for Age, Sex, and Race
* Comparable results for AUC and 2hr markers

14. Vitamin D On Glucose and Insulin?
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml) -0.073 0.186 -0.114 0.037 -0.085 0.121 0.047 0.390
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml)
Model 1: Controlling for Age, Sex, and Race * Comparable results for AUC and 2hr markers

15. Vitamin D On Glucose and Insulin?
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml) -0.073 0.186 -0.114 0.037 -0.085 0.121 0.047 0.390
Model 1: Controlling for Age, Sex, and Race * Comparable results for AUC and 2hr markers

16. Android FMI
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml) -0.054 0.346 -0.080 0.129 -0.085 0.127 0.059 0.290
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml) -0.073 0.186 -0.114 0.037 -0.085 0.121 0.047 0.390
Model 1: Controlling for Age, Sex, and Race
Model 2: Controlling for Age, Sex, Race, and Android FMI
Adjusting for Regional Adiposity?
* Comparable results for AUC and 2hr markers
Android FMI
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml)

17. Android FMI
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml) -0.054 0.346 -0.080 0.129 -0.085 0.127 0.059 0.290
Fasting Glucose Fasting Insulin HOMA-IR ISI
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml) -0.073 0.186 -0.114 0.037 -0.085 0.121 0.047 0.390
Model 1: Controlling for Age, Sex, and Race
Model 2: Controlling for Age, Sex, Race, and Android FMI
Adjusting for Regional Adiposity?
* Comparable results for AUC and 2hr markers

18. Summary
• Android adiposity
• fasting glucose and insulin, insulin resistance
• insulin sensitivity & 25(OH)D
• 25(OH)D (-) fasting insulin
• Lost after android FMI or other markers of central adiposity added

19. Conclusion
• The apparent association between 25(OH)D and insulin
sensitivity is largely mediated by central adiposity.
• Decreasing adiposity, particularly central adiposity, should
be considered an important strategy for improving vitamin
D status and whole-body glucose homeostasis.

20. Acknowledgements
• Principle Investigator
• Wayne Campbell, PhD
Co-Investigators
• Original Study
• Eileen Weinheimer-Haus, PhD
• Vitamin D
• James C Fleet, PhD
• Munro Peacock, PhD
• Funding Sources
• U.S. Whey Protein Research Consortium
• NIH T32AG025671
• CTSI UL1TR001108
• USDA Obesity Doctoral Fellowship
Current Lab Staff
• Jung Eun Kim, PhD, RD
• Jing Zhou
• Drew Sayer, MS
• Christian Wright, MS
• Jia Li, MS
• Susannah Gordon, MS, RD
• Akua Amnakwaah
• Amy Wright, RD
• Anne Wilcox, RD
• Jan Green
• Doug Maish

21. Thank you, Any Questions?

23. Adiposity Measures (Beta), P-value (Beta) P-value
BMI (-0.122), 0.027 Appendicular Fat Mass (kg) (-0.055), 0.430
Total FMI (-0.161), 0.018 Appendicular FMI (-0.151), 0.086
Total Body Fat % (-0.169), 0.075 Android Fat Mass (kg) (-0.082), 0.145
Gynoid Fat Mass (kg) (-0.048), 0,480 Android Body Fat % (-0.115), 0.059
Gynoid Body Fat % (-0.101), 0.379 Android FMI (-0.113), 0.042
Gynoid FMI (-0.134), 0.119
Aim 1: Total or regional adiposity?
Model 1: Controlling for Age, Sex, and Race

24. 2hr-Glucose 2hr-Insulin Glucose AUC Insulin AUC
Beta P-value Beta P-value Beta P-value Beta P-value
Peripheral Adiposity
Appendic. Fat Mass (kg) -0.086 0.223 -0.073 0.297 -0.135 0.053 -0.064 0.365
Appendic. FMI -0.098 0.286 -0.067 0.447 -0.150 0.085 -0.042 0.629
Gynoid Fat Mass (kg) -0.086 0.210 -0.059 0.388 -0.120 0.077 -0.038 0.579
Gynoid Body Fat % -0.203 0.078 -0.184 0.109 -0.258 0.024 -0.226 0.048
Gynoid FMI -0.102 0.238 -0.047 0.584 -0.134 0.116 -0.008 0.922
Central Adiposity
Android Fat Mass (kg)* 0.196 <0.001 0.261 <0.001 0.207 <0.001 0.312 <0.001
Android Body Fat % 0.164 0.007 0.202 0.001 0.165 0.006 0.225 <0.001
Android FMI* 0.209 <0.001 0.276 <0.001 0.227 <0.001 0.330 <0.001
Model 1: Controlling for Age, Sex, and Race

25. 25OHD
2hr-Glucose 2hr-Insulin Glucose AUC Insulin AUC
Beta P-value Beta P-value Beta P-value Beta P-value
Central Adiposity
Android Fat Mass (kg)* 0.202 <0.001 0.256 <0.001 0.210 <0.001 0.305 <0.001
Android Body Fat % 0.172 0.005 0.195 0.001 0.169 0.005 0.215 <0.001
Android FMI* 0.217 <0.001 0.269 <0.001 0.233 <0.001 0.321 <0.001
Model 2: Controlling for Age, Sex, Race, and 25(OH)D

26. 2hr-Glucose 2hr-Insulin Glucose AUC Insulin AUC
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml) 0.049 0.373 -0.083 0.131 0.020 0.711 -0.106 0.052
Model 2: Controlling for Age, Sex, Race, and Android FMI
Model 1: Controlling for Age, Sex, and Race
Android FMI
2hr-Glucose 2hr-Insulin Glucose AUC Insulin AUC
Beta P-value Beta P-value Beta P-value Beta P-value
Vitamin D
25(OH)D (ng/ml) 0.074 0.177 -0.056 0.299 0.047 0.383 -0.076 0.149