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Transsphenoidal selective adenomectomy is the most efficient primary treatment for acromegaly. However, management of persistent or recurrent disease remains controversial. The objective of the present study was to evaluate the early and long-term efficacy and safety of a second transsphenoidal surgery performed in those cases. The results of a retrospective study of 16 patients undergoing reoperation by the senior author (J.H.) between 1970 and 1991 are reported. Reoperation was performed for persistent or progressive acromegaly in 11 patients, visual impairment in four, and disease recurrence in one. Normalization of growth hormone (GH) was defined as a basal GH level of less than 5 micrograms/L and suppression to less than 2 micrograms/L during the oral glucose tolerance test. Long-term follow-up data were available in 15 patients. The second transsphenoidal surgery induced a greater than 50% decrease of GH level in 11 patients. Three (19%) of 16 patients were cured according to the authors' criteria and remained so after 2, 7, and 20 years. Two more patients had a postoperative basal GH level of less than 5 micrograms/L but incomplete suppression during the oral glucose tolerance test. Thus, a total of five patients (31%) achieved a basal GH of less than 5 micrograms/L. One other patient who had no initial improvement after the second transphenoidal surgery had spontaneous normalization of his GH level after 13 years. The following complications of the second surgery occurred in three patients: one subarachnoid hemorrhage, two new visual field defects, one cranial nerve palsy, and one meningitis. Moreover, 10 patients (62.5%) developed one or more new pituitary hormone deficiencies. In conclusion, reoperation for persistent or recurrent acromegaly has low success and high complication rates. According to the authors' experience, this procedure should be reserved for patients unresponsive to other forms of therapy or with progressive visual impairment despite medical therapy.

New proposals for the diagnosis of gestational diabetes (GDM), promulgated by the International Association of Diabetes and Pregnancy Study Groups (IADPSG), will substantially increase the number of women diagnosed with GDM. This will have an enormous impact on healthcare resources, diverting attention away from genuinely high risk diabetic pregnancies. Randomized trials in 'mild' GDM indicate that the main effects of treatment are a 2 %-3 % reduction in birth weight, fewer 'big babies', and less shoulder dystocia. However, these studies used different diagnostic criteria, and women diagnosed by the broader IADPSG criteria may not derive the same modest benefit. Modeling indicates a very high cost per QALY, unless later development of type 2 diabetes can be prevented. Far from producing consensus, the IADPSG suggestion has thrown sharply into focus the need to assess critically the risks, costs and benefits of adopting criteria that may pathologize a large number of otherwise normal pregnancies.

Preventive medical interventions should be based on the highest level of scientific evidence. Actual criteria for diagnosing gestational diabetes mellitus (GDM) are neither uniform nor based on pregnancy outcomes. An expert panel from the International Association of Diabetes in Pregnancy Study Groups recently proposed that all pregnant women undergo a one-step 75 g OGTT, and defined new lower cut-off points to diagnose GDM (Metzger BE et al. Diabetes Care 33: 676-682). These criteria will double the prevalence of GDM, as 18% of all pregnant women will be labelled as abnormal. A recent article in Diabetologia (Ryan EA 54:480-486) claimed that maternal glucose is a weak predictor of big babies, that a single OGTT is poorly reproducible, and that expected benefits from intervention would be, at best, modest. This Commentary discusses other objections and argues that guidelines on any new GDM diagnostic strategy should be based on the results of randomised controlled trials rather than on disputable expert opinions.

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