Search Results

You are looking at 1 - 3 of 3 items for

  • Author: Wouter R de Vries x
Clear All Modify Search
Restricted access

Corné A Roelen, Hans P Koppeschaar, Wouter R de Vries, Pierre M Zelissen, Yvonne E Snel, Manorath E Doerga, Jos H Thijssen and Rien A Blankenstein

Roelen CA, Koppeschaar HP, de Vries WR, Zelissen PM, Snel YE, Doerga ME, Thijssen JH, Blankenstein RA. High-affinity growth hormone binding protein, insulin-like growth factor I and insulin-like growth factor binding protein 3 in adults with growth hormone deficiency. Eur J Endocrinol 1996;135:82–6. ISSN 0804–4643

The high-affinity growth hormone binding protein (GHBP) circulates in human blood and represents the extracellular domain of the growth hormone (GH) receptor. The effects of GH deficiency on GHBP in adults are not clear. The aim of this study was to evaluate serum GHBP levels in adults with GH deficiency and to assess whether GHBP measurement may contribute to the diagnosis of adult GH deficiency, based on a two-step model. We measured insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP-3) and GHBP levels in serum samples of 36 patients with adult-onset GH deficiency. The GHBP levels were measured by FPLC size-exclusion chromatography; IGF-I and IGFBP-3 levels were measured by RIA. Serum GHBP levels were elevated above the upper limit of the 95% confidence interval in 26 patients, whereas IGF-I and IGFBP-3 levels were low in 10 patients and in 16 patients, respectively. The combination of low serum IGF-I and low IGFBP-3 levels was found in 10 patients. In nine patients, serum IGF-I levels were low, with elevated GHBP levels. Low serum IGF-I, low IGFBP-3 and elevated GHBP levels were found in five patients. Only four out of 36 patients had serum IGF-I, IGFBP-3 and GHBP levels that were within the 95% confidence interval of the control values. We conclude that adults with acquired GH deficiency have elevated GHBP levels in comparison to healthy subjects. We suggest that measurement of GHBP levels might contribute to the diagnosis of adult GH deficiency, though further research is required to study the additional value of GHBP measurements.

HPF Koppeschaar, Department of Endocrinology, University Hospital Utrecht, HPL00.407, PO Box 85500, 3508 GA Utrecht, The Netherlands

Free access

Sander V Haijma, P Sytze van Dam, Wouter R de Vries, Inge Maitimu-Smeele, Carlos Dieguez, Felipe F Casanueva and Hans P F Koppeschaar

Objective and design: Ageing and obesity result in decreased activity of the GH/IGF-I axis and concomitant impaired GH responses to secretory stimuli. We therefore determined the validity of the GH cut-off value of 15.0 μg/l in the GH-releasing hormone (GHRH)/GH releasing peptide-6 (GHRP-6) test for the diagnosis of GH deficiency in elderly or severely obese men.

Methods: We performed a combined GHRH/GHRP-6 test in ten elderly men (mean age 74 years; mean body mass index (BMI) 24.6 kg/m2), nine obese men (mean age 47 years; mean BMI 40.6 kg/m2) and seven healthy male controls (mean age 51 years, mean BMI 24.3 kg/m2). After assessment of fasting plasma GH, IGF-I and IGF-binding protein-3 (IGFBP-3), GHRH (100 μg) and GHRP-6 (93 μg) were given intravenously as a bolus injection. Repeated GH measurements were performed for two hours. Results: Both peak GH levels and areas under the curve (AUC) were significantly lower in the obese than in the controls (peak 13.2 vs 53.4 μg/l, P = 0.001; AUC 707 vs 3250 μg/l × 120 min; P = 0.001). Mean GH response in the elderly was lower than in the controls (peak 35.0 μg/l; AUC 2274 μg/l × 120 min), but this was not statistically significant. In contrast, GH peak levels in seven obese men remained below the cut-off level of 15.0 μg/l associated with severe GH deficiency. All others had GH peak levels exceeding this threshold. IGFBP-3 levels were significantly lower in the elderly than in the controls (1.35 vs 2.05 mg/l, P = 0.001). Baseline GH or IGF-I did not differ significantly between groups.

Conclusions: GH responses following GHRH/GHRP-6 administration were significantly reduced in severely obese men, but were not significantly reduced in elderly men, despite a negative trend. Our data indicate that the cut-off GH level of 15.0 μg/l after GHRH + GHRP-6 administration for the diagnosis of severe GH deficiency cannot be used in severely obese men.

Restricted access

Daniel J Lobatto, Amir H Zamanipoor Najafabadi, Friso de Vries, Cornelie D Andela, Wilbert B van den Hout, Alberto M Pereira, Wilco C Peul, Thea P M Vliet Vlieland, Wouter R van Furth and Nienke R Biermasz

Objective

Although widely advocated, applying Value Based Health Care (VBHC) in clinical practice is challenging. This study describes VBHC-based perioperative outcomes for patients with pituitary tumors up to 6 months postoperatively.

Methods

A total of 103 adult patients undergoing surgery were prospectively followed. Outcomes categorized according to the framework of VHBC included survival, degree of resection, endocrine remission, visual outcome (including self-perceived functioning), recovery of pituitary function, disease burden and health-related quality of life (HRQoL) at 6 months (Tier 1); time to recovery of disease burden, HRQoL, visual function (Tier 2); permanent hypopituitarism and accompanying hormone replacement (Tier 3). Generalized estimating equations (GEEs) analysis was performed to describe outcomes over time.

Results

Regarding Tier 1, there was no mortality, 72 patients (70%) had a complete resection, 31 of 45 patients (69%) with functioning tumors were in remission, 7 (12%, with preoperative deficits) had recovery of pituitary function and 45 of 47 (96%) had visual improvement. Disease burden and HRQoL improved in 36–45% at 6 months; however, there were significant differences between tumor types. Regarding Tier 2: disease burden, HRQoL and visual functioning improved within 6 weeks after surgery; however, recovery varied widely among tumor types (fastest in prolactinoma and non-functioning adenoma patients). Regarding Tier 3, 52 patients (50%) had persisting (tumor and treatment-induced) hypopituitarism.

Conclusions

Though challenging, outcomes of a surgical intervention for patients with pituitary tumors can be reflected through a VBHC-based comprehensive outcome set that can distinguish outcomes among different patient groups with respect to tumor type.