Koskimies Janne, Heinonen Sini, Jukarainen Sakari, Ek Viktoria, Hakkarainen Antti, Lundbom Nina, Borén Jan, Pietiläinen Kirsi, Taskinen Marja-Riitta, Söderlund Sanni, Matikainen Niina

Adipocyte size in obesity with and without metabolic syndrome

AIM 

In obesity, adipose tissue undergoes changes, which possibly lead to adipose tissue dysfunction associated with insulin resistance, dyslipidemia and ectopic fat accumulation. We investigated whether adipocyte size 1) increases in obesity with metabolic syndrome (MetS) development, and 2) associates with adverse metabolic changes.

METHODS

We recruited 131 subjects: n=54 obese subjects without MetS (BMI 27- 40 kg/m2), n=47 obese subjects with MetS (BMI 27- 40 kg/m2), and n=30 healthy subjects with normal BMI <25 kg/m2. Subcutaneous abdominal adipocyte size from biopsies was measured under a light microscope.
 
RESULTS

Obese subjects had larger adipocyte size than subjects with normal BMI. However, adipocyte size did not differ between obesity with MetS and obesity without MetS (94.0 ± 15.9 vs 96.5 ± 14.0 um, p=n.s.). In only 20 % of subjects with normal BMI, the mean adipocyte size was in the two largest quartiles, whereas this was the case in 54 -62 % of obese subjects.


Obese subjects with MetS had adverse metabolic profile (high visceral and liver fat, elevated blood pressure, insulin resistance, adverse lipid composition including increased VLDL and decreased HDL2) as compared to obese subjects without MetS and subjects with normal BMI. In a multivariate regression analysis, age, blood pressure, triglycerides, and Matsuda index were significantly associated with adipocyte size. 

CONCLUSIONS

In obesity, adipocyte size is increased regardless of MetS. The data suggest that as adipocyte size in obesity reaches a certain threshold, lipid overflow predisposes to multiple adverse metabolic changes in the presence of insulin resistance.

02 - ADIPOCYTE SIZE IN OBESITY WITH AND WITHOUT METABOLIC SYNDROME