DOES TREATMENT OF ACROMEGALY AFFECT LIFE EXPECTANCY

Previous studies have demonstrated a twofold to threefold increase in mortality in acromegalic patients largely due to increased cardiovascu lar disease, but also in some series due to increased malignant diseas e. In a retrospective analysis of 79 patients from one large hospital center in the United Kingdom, we sought to determine (1) whether the i ncreased mortality persists and (2) what is the relationship between m ortality and growth hormone (GH) levels achieved following treatment. Hospital records and death certificates were scrutinized and serum GH data collected from patients treated between 1967 and 1991. GH assessm ents were performed on average annually during follow-up evaluation an d consisted of 3-hour measurements during waking hours in a GH day ser ies. The average value was calculated from five readings. We used the lowest value, usually the most recent, for average GH achieved during the follow-up period. There were 29 males and 50 females, and no numer ical difference between sexes was found in living and deceased groups. The mortality of the cohort was compared with that of the general pop ulation, and expected mortality was calculated from Office of Populati on Census Statistics data. The observed to expected ratio was determin ed. There were no differences between living and deceased groups in th e proportion of subjects with hypertension, diabetes, or visual field defects at the time of diagnosis. Most patients were treated with radi otherapy +/- bromocriptine as primary therapy. There was a marked shif t to lower mean GH values with treatment such that 48 of 79 had values less than 10 mU/L. Those subjects with mean GH levels less than 5 mU/ L had significantly lower serum insulin-like growth factor-l (IGF-IJ v alues than subjects with values above this level. The observed to expe cted mortality ratios (with 95% confidence intervals in parentheses) w ere as follows: males, 2.55 (1.4-4.3), P =.002; females, 2.83 (1.6-4.8 ), P =.001; total, 2.63 (1.8-3.9), P <.001; lowest GH less than 10 mU/ L, 2.01 (0.9-3.83), P =.039; and lowest GH less than 5 mU/ L, 1.42 (0. 46-3.31), P = .28. These results show that overall mortality in both m ales and females with acromegaly is still two to four times that of th e general population. However, the important novel finding is that if GH levels of less than 5 mU/L can be achieved, there is no increased m ortality. The median age of death (62 years) was similar to that found previously; 57% of deaths were due to vascular causes, 25% to respira tory disease. and 11% to malignancy. Small numbers of deaths precluded statistical comparison with the general population. The implication o f these preliminary data is that if serum GH levels can be reduced to less than 5 mU/L by treatment, the long-term outlook for acromegalic p atients is very good. These data need to be confirmed with a larger co hort of patients. (C) 1995 by W.B. Saunders Company