Oral ghrelin receptor agonist MK-0677 increases serum insulin-like growth factor 1 in hemodialysis patients: a randomized blinded study

Abstract

Background: Protein-energy wasting (PEW) in end-stage renal disease (ESRD) patients is associated with increased morbidity and mortality, but options for treatment are limited. Growth hormone (GH) increases insulin-like growth factor 1 (IGF-1), with improved nutritional parameters, but must be given subcutaneously and does not provide normal GH secretion patterns. MK-0677, an oral ghrelin receptor agonist (GRA), maintains normal GH secretion and increases lean body mass in normal subjects; it has not been studied in dialysis patients, an essential step in assessing efficacy and safety prior to clinical trials.

Methods: We performed a randomized crossover double-blind study in assessing the effect of MK-0677 versus placebo on IGF-1 levels, the primary outcome, in hemodialysis patients. In total, 26 subjects enrolled and 22 completed the 3-month crossover study.

Results: The geometric mean IGF-1 was 1.07-fold greater [95% confidence interval (CI) 0.89-1.27; P = 0.718] after placebo. In patients receiving MK-0677, the geometric mean IGF-1 were 1.76-fold greater (95% CI 1.48-2.10; P < 0.001) following MK-0677. When the data were adjusted for preintervention IGF-1 concentration, the ratio of geometric means (MK-0677 relative to placebo) for the pre- versus postintervention change in the IGF-1 was 1.65 (95% CI 1.33-2.04; P < 0.001). These data demonstrate a 65% greater increase (95% CI 33-104%) in IGF-1 in MK-0677-dosed subjects compared with placebo. There were no serious adverse effects attributable to MK-0677.

Conclusions: MK-0677 increased serum IGF-1 levels with minimal adverse effects in hemodialysis subjects. Studies are needed to evaluate whether long-term therapy with MK-0677 improves PEW, lean body mass, physical strength, quality of life and survival in CKD/ESRD patients.

FIGURE 1

Postintervention:preintervention ratio of IGF-1 and GH geometric means. Circles identify the geometric mean ratio and the vertical lines identify the 95% CIs for the geometric mean ratio. Hatch lines denote the reference line for a geometric mean ratio equal to 1. P-values correspond to the test of the null hypothesis that the ratio of geometric means is the same irrespective of the intervention.

FIGURE 2

Change in body weight from pre- to postintervention. Circles identify the mean change in body weight and the vertical lines identify the 95% CI for the mean change. Hatch lines denote the reference line for a mean change equal to 0. The P-value corresponds to the test of the null hypothesis that the mean change in body weight (kg) is the same irrespective of the intervention.