There are limited data inquiring the relationship between somatostatin analogues and insulin sensitivity among acromegalic cases. This study was conducted to evaluate short-term effects of lanreotide autogel (LA), administered every 28 days by deep subcutaneous injection, on insulin sensitivity among acromegalic patients with pituitary tumors. Before and following six months of LA treatment, insulin resistance and beta-cell function were calculated by using homeostasis model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-beta) formula, and euglycemic hyperinsulinemic clamp test was performed for evaluating the whole insulin sensitivity. Naïve acromegalic patients (Case 1, Case 3) and cases who experienced any prior unsuccessful treatment modality and approved to consume LA (Case 2, Case 4, Case 5) were included. The study was approved by the local ethics committee. Euglycemic hyperinsulinemic clamp defined by De Fronzo was used and insulin sensitivity was derived from glucose disposal rate expressed as mg/kg/min and indicated as M index. The characteristics of the cases regarding serum growth hormone (GH) levels and insulin sensitivity markers during follow-up are shown in Table. Although there were statistically insignificant difference between baseline and final GH, HOMA-IR, HOMA-beta% and M values (P=0.150, P=0.447, P=0.158, P=0.151, respectively), remarkable M value improvement was observed in Case 1, Case 2 and Case 3. This finding might be explained by the prominent decrease in their GH levels following LA treatment.
|Case 1||Case 2||Case 3||Case 4||Case 5|
|HOMAI-IR*||2.32 / 2.25||2.31 / 0.41||4.29/ 5.59||3.23 / 2.59||4.36/3.45|
|HOMAI-beta (%)*||95/ 58.48||289.15 / 83.63||152.25/ 98.06||76.87 /67.14||228.91/218.05|
|M value*||1.03 / 8.22||2.98 / 4.70||5.09 / 13.09||5.72 /5.53||3.90/3.35|
|*Baseline/ following 6 months of treatment.|