24983748
OBJECTIVE	Weight loss reduces risk factors associated with obesity .
OBJECTIVE	However , long-term metabolic improvement remains a challenge .
OBJECTIVE	We investigated quantitative gene expression of subcutaneous adipose tissue in obese individuals and its relationship with low calorie diet and long term weight maintenance induced changes in insulin resistance .
METHODS	Three hundred eleven overweight and obese individuals followed a dietary protocol consisting of an 8-week low calorie diet followed by a 6-month ad libitum weight-maintenance diet .
METHODS	Individuals were clustered according to insulin resistance trajectories assessed using homeostasis model assessment of insulin resistance ( HOMA-IR ) index .
METHODS	Adipose tissue mRNA levels of 267 genes selected for regulation according to obesity , metabolic status and response to dieting was assessed using high throughput RT-qPCR .
METHODS	A combination of discriminant analyses was used to identify genes with regulation according to insulin resistance trajectories .
METHODS	Partial correlation was used to control for change in body mass index .
RESULTS	Three different HOMA-IR profile groups were determined .
RESULTS	HOMA-IR improved during low calorie diet in the 3 groups .
RESULTS	At the end of the 6-month follow-up , groups A and B had reduced HOMA-IR by 50 % .
RESULTS	In group C , HOMA-IR had returned to baseline values .
RESULTS	Genes were differentially expressed in the adipose tissue of individuals according to groups but a single gene , CIDEA , was common to all phases of the dietary intervention .
RESULTS	Changes in adipose tissue CIDEA mRNA levels paralleled variations in insulin sensitivity independently of change in body mass index .
RESULTS	Overall , CIDEA was up-regulated in adipose tissue of individuals with successful long term insulin resistance relapse and not in adipose tissue of unsuccessful individuals .
CONCLUSIONS	The concomitant change in adipose tissue CIDEA mRNA levels and insulin sensitivity suggests a beneficial role of adipose tissue CIDEA in long term glucose homeostasis , independently of weight variation .
BACKGROUND	ClinicalTrials.gov NCT00390637 .

