Join the discussion on: Effects of LF Diet on glucose, insulin and IR in the WHI Trial

This seemed like a good paper to discuss in our next installment of the discussion of scientific literature.  Since this is a new concept, I'll briefly describe what I'm doing here and let y'all have at it!  I am embedding a discussion topic from the Meeting Rooms in this blog post (this time I'll shut off comments, if you want to give some input/feedback on this concept in general, add your thoughts to the comments on the inaugural post).  This time the PDF is being shared through Google docs so everyone can have access to the full text.  All are welcome to join and I hope you will!  I have some thoughts on this one, but will probably lurk and wait until hopefully a few folks have added their says.  I realize some made comments already on another thread regarding this.  If it's not too much trouble perhaps you can C&P them into the discussion here.   Hat tip to O'Primitivo for bringing this up.

Let's discuss!

Effects of LF Diet on glucose, insulin and IR in the WHI Trial
James M Shikany, Karen L Margolis, Mary Pettinger, Rebecca D Jackson, Marian C Limacher, Simin Liu, Lawrence S Phillips, and Lesley F Tinker.   Am J Clin Nutr 2011;94:75–85.

Background: Glycemic effects of the Women’s Health Initiative (WHI) low-fat dietary intervention are unknown.  

Objective: Our objective was to analyze the effects of the WHI low-fat dietary intervention on serum glucose and insulin and insulin resistance up to 6 y after random assignment.  

Design: Postmenopausal WHI Dietary Modification trial intervention (DM-I) and comparison (DM-C) participants with blood measures at least at baseline and year 1 (n = 2263) were included.   Anthropometric measures, dietary assessments, serum glucose and insulin concentrations, homeostasis model assessment of insulin resistance (HOMA-IR) measures, and quantitative insulin sensitivity check index (QUICKI) values were obtained at baseline, year 1, year 3, and year 6.   Changes in measures were compared between groups at years 1, 3, and 6 overall and within stratified analyses.  

Results: Mean (6SD) differences in changes at year 1 between the DM-I and DM-C groups were as follows: glucose, 21.7 6 17.9 mg/dL; insulin, 20.7 6 5.1 lIU/mL; HOMA-IR, 20.2 6 1.9; and QUICKI, 0.004 6 0.019 (all P , 0.05). Similar findings resulted from repeated-measures analyses comparing the intervention and
comparison groups over the 6 y. Whereas normoglycemic women at baseline had a decrease in glucose at year 1 that was 1.9 6 17.2 mg/dL greater in the DM-I than in the DM-C group, diabtic women had an increase in glucose that was 7.9 6 20.3 mg/dL greater in the DM-I than in the DM-C group (P for interaction ,0.001).

Conclusions: A low-fat diet was not significantly associated with adverse glycemic effects up to 6 y after random assignment in postmenopausal women.   However, diabetic women experienced adverse glycemic effects of the low-fat diet. 

Effects of LF Diet on glucose, insulin and IR in the WHI Trial