Search Results

You are looking at 1 - 2 of 2 items for

  • Author: J Thiery x
Clear All Modify Search
Free access

J Kratzsch, I Knerr, A Galler, T Kapellen, K Raile, A Körner, J Thiery, J Dötsch and W Kiess

Objective: Type 1 diabetes mellitus (T1DM) leads to increased serum levels of the soluble leptin receptor (sOB-R) by an as yet unknown cellular mechanism. The aim of our study was to investigate potential metabolic factors that may be associated with the induction of the sOB-R release from its membrane receptor.

Materials and methods: Twenty-five children (aged between 1.5 and 17.0 years) were studied at the onset of T1DM. Blood samples were collected before (n = 25), during the first 18 h (mean ± S.D. 11.1 ± 4.3 h, n = 16) and 92 h (47.5 ± 22.5 h; n = 14) after beginning insulin therapy. Serum sOB-R and leptin levels were determined by in-house immunoassays.

Results: The sOBR-level and the molar sOB-R/leptin ratio were significantly higher before than after starting insulin treatment (P < 0.05). In contrast, leptin levels were significantly lower (P < 0.05) before insulin therapy. The correlation between sOB-R and blood glucose (r = 0.49; P < 0.05), as well as sOB-R with parameters of ketoacidosis, such as pH (r = −0.72), base excess (r = −0.70), and bicarbonate (r = −0.69) (P < 0.0001) at diagnosis of T1DM remained significant during the first 18 h of insulin treatment. Multiple regression analysis revealed that base excess predicted 41.0% (P < 0.001), age 16.4% (P < 0.05), and height SDS 13.9% (P < 0.01) of the sOB-R variance.

Conclusions: Metabolic decompensation in children with new onset T1DM is associated with dramatic changes of the leptin axis; serum levels of sOB-R are elevated and of leptin are reduced. The molar excess of sOB-R over leptin (median 11.3) in this condition may contribute to leptin insensitivity. Upregulation of the soluble leptin receptor appears to be a basic mechanism to compensate for intracellular substrate deficiency and energy-deprivation state.

Free access

I V Wagner, C Paetzold, R Gausche, M Vogel, A Koerner, J Thiery, C G Arsene, A Henrion, B Guettler, E Keller, W Kiess, R Pfaeffle and J Kratzsch

Context

Cutoff limits of GH stimulation tests to diagnose GH deficiency (GHD) in children and adolescents are not sufficiently validated by clinical studies due to discrepancies in the performance of GH immunoassays and lack of available study populations.

Objective

We aimed to establish new cutoff limits for GH stimulation tests based on clinical evidence and compared these immunoassay-based values with an antibody-independent mass spectrometric method.

Design and setting

In a retrospective study, GH cutoff limits for eight different immunoassays and isotope dilution mass spectrometry (ID-MS) were calculated from hGH peak concentrations of short-statured children with and without GHD.

Patients

We compared the serum GH peak concentrations at GH stimulation test of 52 short-statured children and adolescents, who have normal GH secretion at initial workup and normal growth in the follow-up, with the serum GH peak concentrations of 44 GHD patients in the same age range, in order to optimize the cutoff limit calculation.

Results

Discriminant analysis of re-measured GH led to a new cutoff limit of 7.09 μg/l using the iSYS assay (IDS) and the limits for the other seven hGH assays varied between 4.32 and 7.77 μg/l. For ID-MS, cutoffs of 5.48 μg/l (22k GH) and 7.43 μg/l (total GH) were ascertained.

Conclusion

The establishment of method-specific clinical evidence-based GH cutoff limits is of importance to ensure adequate clinical diagnosis and treatment of children and adolescents with GHD. ID-MS may become an important tool for providing both reliable and sustainable SI traceability of GH measurements in the future.