Impaired cardiac performance in elderly patients with growth hormone deficiency

Several evidences indicate that GH and/or insulin-like growth factor I (IGF -I) are involved in the regulation of cardiovascular function. In patients with childhood and adulthood-onset GH deficiency (GHD), the impairment of c ardiac performance is manifest primarily as a reduction in the left Ventric ular (LV) mass (LVM), inadequacy of LV ejection fraction both at rest and a t peak exercise, and abnormalities of LV diastolic filling. No study has be en reported to date in elderly GHD patients that investigated cardiac funct ion. In particular, it is unknown whether cardiac function is modified in a ccordance with patients' age as a physiological response to aging, as in no rmal subjects the rate and extent of LV filling are reduced with age. This study was designed to evaluate heart morphology and function, by echocardio graphy and equilibrium radionuclide angiography, respectively, in rigorousl y selected elderly patients with GHD but without evidence of other complica tions able to affect cardiac performance. Eleven patients with hypopituitar ism (6 men and 5 women, aged 60-72 yr) and 11 sex- age- and body mass index -matched healthy subjects entered this study. None of the patients and cont rols presented with or had previously suffered from other concomitant disea ses, such as diabetes mellitus, coronary artery diseases, long-standing hyp ertension, and hyperthyroidism, which could affect cardiac function. AU pat ients had been previously operated on via the transsphenoidal and/or transc ranic route for nonfunctioning pituitary adenoma, meningioma, or craniophar yngioma, and 6 of them had been irradiated. Eight patients had FSH/LH insuf ficiency, 5 had TSH insufficiency, and 6 had ACTH insufficiency, appropriat ely replaced. All subjects were tested with the combined arginine plus GHRH test showing a GH response below 9 mu g/L. No significant difference was found in plasma IGF-I levels (49.2 +/- 8.5 vs . 71.8 +/- 7.5 mu g/L) between patients and controls. However, IGF-I levels were lower than the normal range in 8 patients and 3 controls. Interventri cular septum thickness (9.1 +/- 0.2 vs. 9.1 +/- 0.2 mm), LV posterior wall thickness (9.1 +/- 0.2 vs. 9.0 +/- 0.2 mm), and LVM after correction for bo dy surface area (97.6 +/- 1.8 vs. 99.9 +/- 1.5 g/m(2)) mere similar in pati ents and controls. Similarly, the LV ejection fraction at rest was similar in patients and controls (57.1 +/- 28 vs. 63.2 +/- 2.5%; P = NS), and it wa s normal (greater than or equal to 50%) in all controls and in 10 of 11 pat ients. By contrast, the LV ejection fraction at peak exercise was markedly depressed in elderly GHD patients compared to age-matched controls (51 +/- 2.5% vs. 73.3 +/- 3%; P < 0.001). A normal response (greater than or equal to 5% increase compared to basal value) of LV ejection fraction at peak exe rcise was found in 8 controls (72.7%) and in 2 of II patients (18.2%). No d ifference was found in the peak rate of LV filling, whether peak filling ra te was normalized to end-diastolic volume (2.5 +/- 0.2 vs. 2.6 +/- 0.2 end- diastolic volume/s) or stroke volume (4.3 +/- 0.3 vs. 4.0 +/- 0.3 stroke vo lume/s), between patients and controls. Finally, exercise duration was sign ificantly shorter in elderly GHD patients than in age-matched controls (7.2 +/- 2.1 vs. 9.1 +/- 0.2 min; P < 0.01). In the patient group, the GH peak after arginine plus GHRH test was significantly correlated with the LV ejec tion fraction at rest (r = 0.822; P < 0.01), whereas IGF-I was significantl y correlated with the peak rate of LV filling whether the peak filling rate was normalized to end-diastolic volume (r = -0.863; P < 0.001) or stroke v olume (r = -0.616; P < 0.05) or expressed as the ratio of peak filling rate to peak ejection fraction rate (r = -0.736; P < 0.01). Disease duration wa s significantly correlated with heart rate at peak exercise (r = 0.614; P < 0.05) and with systolic and diastolic blood pressures both at rest (r = 0. 745; P < 0.01 and r = 0.650; P < 0.05) and at peak exercise (r = 0.684; P < 0.05 and r = 0.617; P < 0.05). The results of the present study demonstrated:that, as in young and adult G HD patients, cardiac performance was impaired in elderly GHD patients, wher eas cardiac mass was normal. These findings further support the potential u sefulness of GK replacement in elderly hypopituitary patients.