Adipose tissue cellularity in relation to prognosis for weight reduction.
Ninety obese adult women were analysed with respect to adipose tissue cellularity and divided into hypertrophic, hyperplastic and combined groups of obesity. Their spontaneous body weight development was analysed over a period of six years. A reference group, with normal body weight, gained weight at an average of 0.25 kg per year. Patients with hyperplastic and combined forms of obesity gained significantly more (2.5 and 3.1 kg per year, respectively) when essentially untreated. The increase for the patients with hypertrophic obesity did not differ significantly from the reference group. During a standardized treatment period on an energy reduced diet (1100 kcal/day or 4600 kJ/day) the hypertrophic, hyperplastic and combined groups reduced by 11, 15 and 20 kg, respectively. There were strong positive correlations between total weight reduction and rate of weight reduction on the one hand and FCN and initial body weight on the other. The combined and hyperplastic groups were on average able to maintain their reduced weight for 12 and 15 weeks, respectively, while the hypertrophic group managed for 51 weeks. There was a strong negative correlation between duration of steady weight after weight reduction and FCN. When the relapse started the rate of regain was three times faster in the hyperplastic and combined groups than in the hypertrophic group. The rate of regain correlated positively with FCN. Thus, the patients demonstrated a characteristic three phase pattern in weight change with a period of reduction followed by periods of steady weight and of weight gain. The higher FCN, the faster this cycle was completed. It is concluded that the long-term prognosis for weight reduction is worse for hypercellular forms of obesity than for the hypertrophic form. However, this does not mean that patients with hypercellular forms of obesity should not be treated at all since their serious spontaneous weight development might be lessened by repeated treatments.