Correlation between insulin-like growth factor and complexity of glucose timeseries index in patients with newly diagnosed acromegaly: A cohort study

Abstract Background Acromegaly have a high risk of abnormal glucose metabolism. The complexity of glucose time series index (CGI) derived from continuous glucose monitoring (CGM) data could be a novel marker to assess glucose homeostasis. Objective To compare the differences in glucose metabolic characteristics and CGI between acromegaly with normal glucose tolerance (NGT) and healthy subjects. Methods Eight newly diagnosed patients with acromegaly (GH group) and eight age- and gender-matched healthy subjects (Control group) were included in this study. All participants underwent oral glucose tolerance test (OGTT) and 72-hour CGM. A refined composite multiscale entropy analysis was performed on the CGM data to calculate the CGI and we compare the differences in glycemic profiles and CGI between the two groups. Results After OGTT, compared with the control group, patients in the GH group had higher 2h glucose (mmol/L) [GH vs control, 6.7 (6.1, 7.0) vs 5.2 (3.8, 6.3), P < 0.05], 3h glucose [5.1 (3.8, 6.5) vs 4.0 (3.4, 4.2), P < 0.05], mean glucose [6.3 (6.1, 6.5) vs 5.5 (5.1, 5.9), P < 0.05], 2h insulin (mU/L) [ 112.9 (46.8, 175.5) vs 34.1 (17.1, 55.6), P < 0.05], and 3h insulin [26.8 (17.1, 55.4) vs 10.4 (4.2, 17.8), P < 0.05]. CGI was lower in the GH group [2.77 (1.92, 3.15) vs 4.2 (3.3, 4.8), P = 0.008]. Spearman's correlation analysis showed insulin-like growth factor (IGF) (r=-0.897, P < 0.001) and mean glucose (r=-0.717, P < 0.05) were significantly negatively correlated with CGI. Multiple linear stepwise regression showed that IGF-1 (r=-0.652, P < 0.05) was independent factor associated with CGI in acromegaly. Conclusion IGF-1 was significantly associated with CGI, and CGI may serve as a novel marker to evaluate glucose homeostasis in acromegaly.