Increased Mortality in Diabetic Foot Ulcer Patients: The Significance of Ulcer Type.

Diabetic foot ulcer (DFU) patients have a greater than twofold increase in mortality compared with nonulcerated diabetic patients. We investigated (a) cause of death in DFU patients, (b) age at death, and (c) relationship between cause of death and ulcer type. This was an eleven-year retrospective study on DFU patients who attended King's College Hospital Foot Clinic and subsequently died. A control group of nonulcerated diabetic patients was matched for age and type of diabetes mellitus. The cause of death was identified from death certificates (DC) and postmortem (PM) examinations. There were 243 DFU patient deaths during this period. Ischaemic heart disease (IHD) was the major cause of death in 62.5% on PM compared to 45.7% on DC. Mean age at death from IHD on PM was 5 years lower in DFU patients compared to controls (68.2 ± 8.7 years versus 73.1 ± 8.0 years, P = 0.015). IHD as a cause of death at PM was significantly linked to neuropathic foot ulcers (OR 3.064, 95% CI 1.003-9.366, and P = 0.049). Conclusions. IHD is the major cause of premature mortality in DFU patients with the neuropathic foot ulcer patients being at a greater risk.

The GnRH test in the assessment of patients with pituitary and parapituitary lesions: results of a 5-year retrospective study.

OBJECTIVE: To examine the utility of the GnRH (gonadotrophin-releasing hormone) test in the management of patients with pituitary and parapituitary lesions. PATIENTS AND METHODS: A 5-year retrospective study of LH (luteinizing hormone) and FSH (follicle stimulating hormone) responses to GnRH test in patients with HP (hypothalamic-pituitary) disease in a regional endocrine centre. Serum LH and FSH concentrations were measured at baseline and at 20 and 60 min after an intravenous bolus of 100 mcg (micrograms) of GnRH. The GnRH responses were categorised by tumour size, tumour type, and gonadal status. RESULTS: Of the 104 patients studied, 46 were male and 58 were female. There were 50 normal, 38 subnormal and 16 exaggerated LH responses compared with 34 normal 67 subnormal and three exaggerated responses for FSH. Seventy-four patients (71.2%) were hypogonadal. Normal LH responses were achieved in half of the hypogonadal subjects and normal FSH responses in more than a third. Furthermore, the LH responses were exaggerated in nine hypogonadal patients compared with three for FSH. The GnRH test could not differentiate between pituitary or parapituitary lesions either by size or type of lesion. An exception was the male non-functioning adenoma (NFA) sub-group (10 patients, all were hypopituitary, seven were hypogonadal), which demonstrated significant subnormal LH and FSH responses compared with other male and female tumour type sub-groups. CONCLUSIONS: The data from this study indicate that the GnRH test is unhelpful in the clinical assessment of the HP axis in patients with HP disease.

Insulinoma: how reliable is the biochemical evidence?

BACKGROUND AND METHODS: We report a case of insulinoma in which the diagnosis was very challenging as some of the biochemical data were consistently equivocal. In order to assess the relative reliability of the analytical tests, retrospective biochemical data on 45 other cases of histologically confirmed insulinoma were evaluated, enabling the most secure diagnostic process to be identified. RESULTS: The data showed that insulin concentrations alone, although measurable, were equivocal in 17% of cases. The addition of C-peptide values clarified the diagnosis in about 50% of the borderline cases, whilst ketone (beta-hydroxybutyrate) concentrations were low during the prevailing hypoglycaemia in all cases. CONCLUSION: The combination of these three tests is suggested as the most effective method for the biochemical diagnosis of hypoglycaemia due to insulinoma.

Is neuropathic ulceration the key to understanding increased mortality due to ischaemic heart disease in diabetic foot ulcer patients? A population approach using a proportionate model.

Ischaemic heart disease (IHD) is the commonest cause of death in diabetic foot ulcer patients and non-ulcerated diabetic patients, yet the mortality rate of diabetic foot ulcer patients is over twice that of non-ulcerated patients. As the cause of this increased mortality is not understood, we plotted the ratio of deaths due to ischaemic heart disease (IHDn) to other causes of death (i.e. IHDn:OCDn) against age for 242 diabetic foot ulcer patients and 121 controls (non-ulcerated diabetic patients). The IHDn:OCDn ratio rose above 1.0 from age 40 years onwards for diabetic foot ulcer patients, but from age 70 years onwards for controls, demonstrating differentially increased mortalities due to IHD. A population model involving summation of IHDn:OCDn ratios for neuropathic and neuroischaemic diabetic foot ulcer patients calculated an overall increased mortality rate of 1.8 compared with that of non-ulcerated diabetics. The model predicted that a 25% reduction in neuropathic diabetic foot ulcer patients dying from IHD would eliminate the increased mortality, demonstrating that neuropathic rather than ischaemic ulceration defines the cause of increased mortality among diabetic foot ulcer patients.