Cardiovascular effects of a single slow release lanreotide injection in patients with acromegaly and left ventricular hypertrophy.

In our study we assessed the effects of a single i.m. injection of slow-release Lanreotide (30 mg) (SR-L), a new long-acting somatostain analog, on circulating GH levels, baseline cardiac function (M-mode, 2D guided, doppler-echocardiographic study) and cardiopulmonary response to exercise (cycloergometric test, performed using a computer drived, electrically braked cycle ergometer), tested at baseline, after 7 and 14 days from the injection in 10 acromegalic patients (5 M, 5 F, mean age 57.7 +/- 3.1 yrs, body mass index (BMI) 27 +/- 0.8 kg/m2, blood pressure 141 +/- 6.5/82 +/- 3 mmHg). SR-L administration decreased GH levels in acromegalic patients (mean +/- SEM) from 16.1 +/- 6.9 to 10.8 +/- 5.1 micrograms/L (p = 0.045) after 7 days and to 11.9 +/- 5 micrograms/L (p = 0.078) after 14 days from the injection. Moreover, we observed a significant (p < 0.05) decrease in systolic blood pressure and heart rate at the 7th (135 +/- 6.1 vs 141 +/- 6.5 mmHg, and 68 +/- 2.1 vs 74 +/- 2.1 bpm) and 14th (137 +/- 6.2 vs 141 +/- 6.5 mmHg, and 72 +/- 2 vs 74 +/- 2.1 bpm) day of the study with respect to the baseline values. After SR-L administration we also found an increase in ejection fraction (69 +/- 2 vs 63 +/- 2.3% at 7th day, p = 0.006; 65 +/- 2.3 vs 63 +/- 2.3% at the 14th day, p = 0.027) and shortening fraction (40.8 +/- 1.8 vs 36.6 +/- 1.9% at 7th day, p = 0.005; 38.7 +/- 1.8 vs 36.6 +/- 1.9% at the 14th day, p = 0.045). The positive acute cardiac response to SR-L injection was also demonstrated by the increase in A/E velocity ratios at 7th (1.14 +/- 0.1 vs 0.98 +/- 0.07, p = 0.016) and 14th (1.04 +/- 0.08 vs 0.98 +/- 0.07, p = 0.008) day of the study. After SR-L injection, exercise capacity and VO2 at anaerobic threshold were also increased with respect to the baseline test: 61.1 +/- 8.2 vs 38.9 +/- 6.8 watts (p = 0.002) and 1012.4 +/- 71.5 vs 915.3 +/- 77.8 mL/min (p = 0.033) after 7 days, and 61.4 +/- 7.2 vs 38.9 +/- 6.8 watts (p = 0.002) and 1010.1 +/- 62.5 vs 915.3 +/- 77.8 mL/min (p = 0.010) after 14 days from the injection. In conclusion, these results suggest that in acromegalic patients: (1) SR-L causes a rapid improvement in baseline cardiac function and in cardiopulmonary performance during exercise in acromegaly; (2) the endocrine (decrease in GH levels) and echocardiographic responses to SR-L are maximal after 7 days from the injection, whereas the effect of SR-L on the exercise performance are longer lasting.