Table 3.

Overview of the methods, cut-off and statistical reporting for the oral glucose tolerance test (n = 11), ordered by frequency

OGTT analysis	Number of studies (%)	References
Method
2 h period: pre-dose, 30, 60, 120 min	1 (9%)	[24]
2 h period: 30, 60, 90, 120 min	1 (9%)	[45]
3 h period: pre-dose, 30, 60, 90, 120, 180 min	1 (9%)	[33]
Not reported	8 (73%)	[27, 30, 38, 59, 61–63, 67]
Glucose administration
75 g	5 (45%)	[24, 27, 33, 45, 59]
Not defined	6 (55%)	[30, 38, 61–63, 67]
Nadir cut-off for biochemical control
< 1 ng/ml	5 (45%)	[24, 33, 59, 62, 67]
< 0.4 ng/ml	1 (9%)	[67]
< 1 µg/dl	1 (9%)	[61]
< 2 mU/L	1 (9%)	[27]
No cut-off reported/used	4 (36%)	[30, 38, 45, 63]
Summary statistics
% Biochemical control	5 (45%)	[24, 27, 33, 61, 62, 67]
Individual levels	3 (27%)	[24, 30, 38]
Mean ± SD	3 (27%)	[24, 33, 63]
Median (IQR)	3 (27%)	[24, 45, 59]
% Nadir change from baseline mean ± SD	1 (9%)	[24]
Mean ± SD [range]	1 (9%)	[30]
Mean ± SD pre-glucose GH	1 (9%)	[24]
Median	1 (9%)	[62]
Median (IQR) pre-glucose GH	1 (9%)	[24]
Growth hormone assay reported
Yes (%)	7 (64%)	[30, 33, 45, 59, 61, 63, 67]

SD Standard deviation, IQR interquartile range