Urinary growth hormone level and insulin-like growth factor-1 standard deviation score (IGF-SDS) can discriminate adult patients with severe growth hormone deficiency.
Hirohata. Toshio T; Saito. Nobuhito N; Takano. Koji K; Yamada. So S; Son. Jae-Hyun JH; Yamada. Shoko M SM; Nakaguchi. Hiroshi H; Hoya. Katsumi K; Murakami. Mineko M; Mizutani. Akiko A; Okinaga. Hiroko H; Matsuno. Akira A
Key Findings
- IGF‑1 standard deviation score (IGF‑1 SDS) was much lower in patients with severe AGHD (average -2.07) than in those without (-0.03).
- A cutoff of IGF‑1 SDS < ‑1.4 or undetectable urinary GH correctly identified most cases of severe AGHD with high sensitivity.
- Urinary GH measurement at awakening correlated strongly with AGHD status (χ² test statistic 7.01, p < 0.01).
Practical Outcomes
- For self‑trackers, measuring IGF‑1 (using a lab test that provides an age‑adjusted SDS) and checking first‑morning urinary GH could serve as a low‑cost screening tool before deciding on a formal GHRP‑2 stimulation test. If IGF‑1 SDS is below -1.4 or urinary GH is undetectable, it suggests a likely GH deficiency that may warrant further clinical evaluation or cautious use of GH‑boosting peptides.
Summary
The study shows that measuring IGF‑1 levels (adjusted for age and sex) and checking for the presence of growth hormone in first‑morning urine can reliably flag severe adult growth‑hormone deficiency, which is usually confirmed with a GHRP‑2 stimulation test.
Abstract
Adult growth hormone (GH) deficiency (AGHD) in Japan is diagnosed based on peak GH concentrations during GH provocative tests such as GHRP-2 stimulation test. In this study, we aimed to evaluate the ability of serum insulin-like growth factor-1 (sIGF-1) and urinary GH (uGH) at the time of awakening to diagnose AGHD. Fifty-nine patients with pituitary disease (32 men and 27 women; age 20-85 y (57.5 ± 15.5, mean ± SD) underwent GHRP-2 stimulation and sIGF-1 testing. Thirty-six and 23 patients were diagnosed with and without severe AGHD, respectively based on a peak GH response of <9 ng/mL to GHRP-2 stimulation. Serum IGF-1 was evaluated as a standard deviation score (IGF-1 SDS) based on age and sex. We determined whether uGH levels in urine samples from 42 of the 59 patients at awakening were above or below the sensitivity limit. We evaluated IGF-1 SDS and uGH levels in a control group of 15 healthy volunteers. Values for IGF-1 SDS were significantly lower in patients with, than without (-2.07 ± 1.77 vs.-0.03 ± 0.92, mean ± SD; p < 0.001) AGHD whereas the range of IGF-1 SDS substantially overlapped at > -1.4. IGF-1 SDS discriminated AGHD more effectively in patients aged ≤60 years. The χ2 test revealed a statistical relationship between uGH and AGHD (test statistic: 7.0104 ≥ χ2 (1; 0.01) = 6.6349). When IGF-1 SDS is < -1.4 or uGH is below the sensitivity limit, AGHD can be detected with high sensitivity.
Study Information
pubmed
2012
2012-11-29T00:00:00.000Z
10.1507/endocrj.ej12-0196