OBJECTIVES: The available T2DM (Type 2 Diabetes Mellitus) therapies attend with weight gain, which affects for the disease outcomes in a very extent way. Weight gain could worsen the long term effect of insulin therapy (increased risk of insulin resistance, hypertension, dyslipidemia), which influences the total treatment cost. Long-acting insulin analogue therapies (insulin detemir and glargine) offer improved pharmacokinetic and pharmacodynamic properties compared to regular human insulin. In a previous meta-analysis detemir caused significant lower weight gain than glargine (-2.04 kg after 6 months therapy). Our research aimed to determine the effects of weight gain and calculate the total treatment cost. METHODS: On the basis of a systematic literature review we found many consequences, which could be obesity related. Because of its important effect and bride prevalence, we analyzed the CHD (coronary heart disease) risk changes related to the weight gain. We modified the 10 years risk - calculated with the UKPDS risk engine – with the effects of the weight gain published in a meta-analysis. We aggregated the differences in natural outcomes (number of avoided fatal and non fatal events) and in monetary unit, based on real world data. RESULTS: In our analysis we assessed, that insulin detemir treated patients – due to the favourable features regarding weight gain compared to glargine – experience smaller (cca 2 %) CHD risks. It means for the current treated Hungarian population that there are 223 coronary (158 fatal of this) events avoidable in 10 years horizon using detemir insulin instead glargine. The estimated savings of social insurance would be around 224 million HUF on the basis of a Hungarian burden of diabetes complication study. CONCLUSIONS: Obesity and weight gain related aspects should be priorised as the main international tendencies showed. It’s not only necessary on the policy level, but also in “indivual” level in the cost-effectiveness analysis as well.