Clonidine stimulation test: Is single best time point, convenient yet efficacious?

Abstract

Context:To find a single time point during clonidine stimulation test (CST), with highest diagnostic value to rule out growth hormone deficiency (GHD).Settings and Design:This is a retrospective study of 79 CSTs carried out in a tertiary care center in India.Materials and Methods:A cohort of 79 children with unexplained short stature was divided into two groups: GHD and non-GHD. Any one stimulated growth hormone (GH) level >10 ng/mL was used to rule out GHD. Diagnostic accuracy of not only single time points but also time points in pairs was calculated.Statistical Analysis:The data were analyzed using SPSS statistical software 22.0. Descriptive statistics were used for analyzing demographic data. Mode for time to peak GH was calculated in each group. The specificity and false positive rates at each time point as well as combined time points were determined.Results:Assaying a single sample at 60 min after clonidine resulted in 20.5% false positive tests with specificity of 79.5%. Addition of the 90 min sample increased specificity to 92.3%.Conclusion:The 60 min sample after clonidine stimulation was the best single sample to rule out GH deficiency. Combined sampling at 60 min + 90 min is economical and less cumbersome, with minimal compromise on the specificity.

Association between lipid profile and other biochemical parameters with growth hormone in children and adolescents with short stature

“…The results presented here are consistent with a previous investigation (Bhagwat et al, 2018) that reported a non-signi icant difference between basal GH levels in patients and control. It may be due to the release of growth hormone, which is pulsated with diurnal variation, under a negative feedback autoregulation loop, and may be affected by various factors.…”

“…and GH3 (after 1.5 hr.) correspond to the results reported in a previous study (Bhagwat et al, 2018) . It may be due to the pulsatile way of GH secretion and the increase after the stimulation.…”

Reliability of Agreement between Insulin, Clonidine, and Glucagon Stimulation Tests for the Diagnosis of Growth Hormone Deficiency in Children: A Retrospective Cohort Study

“…Only somnolence and mild hypotension were observed and did not require oral hydration or saline infusion, as reported by several studies [ 33 , 34 ]. Regarding convenience and cost-effectiveness, another study assessed whether minimizing the sampling points could reduce costs while maintaining the efficacy and sensitivity of the test and concluded that a sample obtained 60 min after clonidine stimulation was the best single sample for ruling out GHD, with 79.5% specificity [ 35 ]. However, Gillis et al reported that the peak indicating GH sufficiency (85.15%) during the CST tended to occur more frequently at typical times (60 min and 90 min) than those indicating GHD (68%) [ 36 ].…”

Use of the Growth Hormone Stimulation Test Result in the Management of Patients With a Short Stature

“…The relatively long duration of the procedure, up to four hours, is considered a disadvantage of the test [ 5 ]. The clonidine stimulation test (CST) is the preferred test in diagnosing children with GHD [ 6 ]. Clinically, there is no standardized peak time with CST as the GH response peak time could be early or late.…”

“…Thakur et al found that the 60 minutes post-CST measurement is the most important to exclude GHD (79.5% specificity). The addition of the 90 minutes raises the test’s specificity to 92.3% [ 6 ].…”