A 24-hour comparison of serum growth hormone concentrations in patients with heart failure versus healthy controls

Evaluation of pulsatile plasma concentrations of growth hormone in healthy dogs and dogs with dilated cardiomyopathy

OBJECTIVE

To evaluate plasma concentrations of growth hormone (GH) and insulin-like growth factor I (IGF-I) in healthy dogs and large-breed dogs with dilated cardiomyopathy (DCM).

ANIMALS

8 dogs with DCM and 8 healthy control dogs of comparable age and body weight.

PROCEDURES

Blood samples for determination of the pulsatile plasma GH profile were collected from all dogs at 10-minute intervals between 8:00 am and 8:00 pm. Plasma IGF-I concentration was determined in the blood sample collected at 8:00 am.

RESULTS

No significant differences in plasma IGF-I concentrations, basal plasma GH concentration, GH pulse frequency, area under the curve above the zero line and above the baseline for GH, and GH pulse amplitude were found between dogs with DCM and control dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results did not provide evidence for an association between DCM in dogs and a reduction in plasma concentrations of GH or IGF-I. Therefore, reported positive effects of GH administration are most likely attributable to local effects in the heart.

Beneficial effects of high doses of growth hormone in the introduction and optimization of medical treatment in decompensated congestive heart failure

BACKGROUND

Optimizing oral therapy in patients with unstable decompensated and/or dobutamine-dependent congestive heart failure (CHF) is a challenge.

METHODS AND RESULTS

We investigated the effects of high doses of recombinant human growth hormone (GH) in 6 patients with cardiac cachexia and unstable decompensated CHF (5 dobutamine-dependent), including its influence in the optimization of oral CHF treatment. Patients received 8 IU of subcutaneous GH per day for median 26 (range 61) days. GH improved the systolic systemic blood pressure (SSBP, in mm Hg) from median 85 (range 34) to 100 (20) (p<.01), and the left ventricular (LV) ejection fraction (in %) from median 23 (range 22) (pretreatment) to 28 (18) (posttreatment) and 38 (28) (later) (p<.007). The NYHA functional class improved from IV to I in 2 patients, from IV to II in 3, and from IV to II-III in one. All patients were discharged from the hospital. It was possible in the hospital to initiate and after discharge to optimize long-term CHF treatment from 37.5 to 50 mg of carvedilol in 5 patients and with higher doses of captopril (from 50 to 150 mg) in all patients. Three patients are alive after 67, 75, and 11 months of follow-up. The remaining 3 patients died from a pulmonary abscess at 9 months, septicemia at 21 months, and progressive heart failure due to unplanned withdrawal of carvedilol at 36 months.

CONCLUSION

The use of GH in patients with decompensated CHF and cardiac cachexia provided clinical stability without the need for inotropic drugs permitting introduction of nonpreviously tolerated drugs. This could represent a new option for optimizing long-term CHF therapy and discharging hospitalized patients who are dobutamine-dependent.

Serum insulin-like growth factor-axis and matrix metalloproteinases in patients with rheumatic arthritis or rheumatic heart disease

BACKGROUND

Insulin-like growth factor (IGF)-I plays an important role for maintaining cardiac functions. We clarified the unknown role of IGF-axis in rheumatic heart disease (RHD).

METHOD

Interleukin (IL)-10, growth hormone (GH), IGF, IGF binding protein (IGFBP)-3 and matrix metalloproteinase (MMP) were measured by ELISA and zymography in 30 age range-matched normal subjects (control), 36 patients with acute phase of rheumatoid arthritis (RA) with positive rheumatoid factor (RF) and C-reactive protein (CRP), and in 43 patients with RHD with negative RF and CRP.

RESULT

Compared with normal subjects, increased IL-10 level and decreased GH were found in RA group whereas unchanged IL-10 and decreased GH were found in RHD group. Compared with age range-matched normal subjects, decreased IGFBP-3, MMP-9 levels, unchanged IGF-I were found in RA group whereas decreased IGF-I levels, unchanged IGFBP3 and increased MMP-9 at age>30 years were found in RHD group. IGF-II was not changed in RA and RHD groups.

CONCLUSION

These findings may imply that during inflammatory phase, the levels of anti-inflammation was high and total IGF-I and IGF bioavailability were maintained in patients with RA. Our findings in RHD may speculate that the long-term reduction of GH and IGF-I as well as the compensating effects of upregulated MMP-9 activity may be partially involved in the long-term pathogenesis from RHD to heart failure. Decreased GH, decreased IGF-I and increased MMP-9 activities may be possible diagnostic markers in RHD for developing heart failure.