Reversal of Type 2 diabetes after bariatric surgery is determined by the degree of achieved weight loss in both short- and long-duration diabetes.

AIM: To define the impact of duration of diabetes and extent of weight loss on the reversibility of Type 2 diabetes after bariatric surgery. METHODS: Complete data were collated from 89 individuals with Type 2 diabetes mellitus undergoing any bariatric surgical procedure in a specialist bariatric centre. People with a preoperative HbA1c < 43 mmol/mol (6.1%) were excluded. Diabetes duration was defined as: short, < 4 years; medium, 4-8 years; and long, > 8 years. RESULTS: An HbA1c of <43 mmol/mol (6.1%) was achieved by 62% of patients in the short-duration group and 26% of patients in the long-duration group. Normoglycaemia was rarely achieved in the long-duration group if weight loss was < 25 kg. In the whole cohort there was a clear relationship of greater weight loss with lower HbA1c levels (Rs = -0.53; P < 0.0001). CONCLUSIONS: The study shows that the degree of achieved weight loss is the major determinant of return to normal blood glucose levels after bariatric surgery. Normoglycaemia can be achieved in long-duration Type 2 diabetes, but a greater degree of weight loss is required than for short-duration diabetes.

A rare ophthalmic presentation of pituitary metastases.

Metastasis to the pituitary gland is very uncommon and a first presentation of any systemic tumour through pituitary metastasis is rare. The authors report an 82-year-old Caucasian woman, well-controlled hypertensive and moderate smoker who presented with worsening diplopia. On ocular motility examination she had partial right third nerve paralysis along with reduced vision in the right eye and headache. MRI brain showed a large growth in the pituitary gland consisting with radiological features of pituitary macroadenoma. The initial chest x-ray showed a non-specific shadow that raised some suspicions and a CT scan of her thorax confirmed a right central bronchial carcinoma. The authors suggest that pituitary gland metastases be considered as part of the differential diagnosis for any patient presenting with a pituitary lesion, as pituitary disease could be the first manifestation of an underlying malignancy.

Real-time assessment of postprandial fat storage in liver and skeletal muscle in health and type 2 diabetes.

Liver and skeletal muscle triglyceride stores are elevated in type 2 diabetes and correlate with insulin resistance. As postprandial handling of dietary fat may be a critical determinant of tissue triglyceride levels, we quantified postprandial fat storage in normal and type 2 diabetes subjects. Healthy volunteers (n = 8) and diet-controlled type 2 diabetes subjects (n = 12) were studied using a novel 13C magnetic resonance spectroscopy protocol to measure the postprandial increment in liver and skeletal muscle triglyceride following ingestion of 13C-labeled fatty acids given with a standard mixed meal. The postprandial increment in hepatic triglyceride was rapid in both groups (peak increment controls: +7.3 +/- 1.5 mmol/l at 6 h, P = 0.002; peak increment diabetics: +10.8 +/- 3.4 mmol/l at 4 h, P = 0.009). The mean postprandial incremental AUC of hepatic 13C enrichment between the first and second meals (0 and 4 h) was significantly higher in the diabetes group (6.1 +/- 1.4 vs. 1.7 +/- 0.6 mmol x l(-1) x h(-1), P = 0.019). Postprandial increment in skeletal muscle triglyceride in the control group was small compared with the diabetic group, the mean 24-h postprandial incremental AUC being 0.2 +/- 0.3 vs. 1.7 +/- 0.4 mmol x l(-1) x h(-1) (P = 0.009). We conclude that the postprandial uptake of fatty acids by liver and skeletal muscle is increased in type 2 diabetes and may underlie the elevated tissue triglyceride stores and consequent insulin resistance.

Effect of insulin therapy on plasma leptin and body weight in patients with type 2 diabetes.

AIMS: This study set out to define relationships between changes in plasma leptin and changes in body weight, plasma insulin and blood glucose control during a 12-month crossover study of once-daily Ultratard or twice-daily Insulatard insulin. PATIENTS AND METHODS: Fasting plasma leptin and insulin were measured during a multicentre cross-over study involving 60 subjects with type 2 diabetes (fasting glucose > 8 mM). After a 2-month run-in, there were two 6-month periods of treatment with Insulatard or Ultratard insulin. RESULTS: Mean plasma leptin increased significantly in both groups after insulin therapy was instigated (12.8 +/- 8.1 to 22.9 +/- 13.1 ng/ml in the Insulatard group; 12.1 +/- 7.2 to 19.2 +/- 12.3 ng/ml in the Ultratard group). Weight also increased significantly in both groups (82.4 +/- 14.3 kg to 88.8 +/- 14.3 kg and 82.2 +/- 15.3 kg to 85.3 +/- 15.2 kg respectively). The increase in plasma leptin correlated well with the increase in weight (R = 0.416, p = 0.001), and this correlation continued after the crossover point. Plasma leptin correlated with BMI throughout the study (R = 0.540, p = 0.000). CONCLUSION: The sustained rise in body weight despite a substantial increase in plasma leptin suggests that either resistance to the hypothalamic action of leptin develops when insulin therapy is begun in type 2 diabetes, or that resetting of the set point for body weight occurs such that a larger body mass is tolerated for a given level of plasma leptin.

Direct assessment of muscle glycogen storage after mixed meals in normal and type 2 diabetic subjects.

To understand the day-to-day pathophysiology of impaired muscle glycogen storage in type 2 diabetes, glycogen concentrations were measured before and after the consumption of sequential mixed meals (breakfast: 190.5 g carbohydrate, 41.0 g fat, 28.8 g protein, 1253 kcal; lunch: 203.3 g carbohydrate, 48.1 g fat, 44.0 g protein, 1497.5 kcal) by use of natural abundance (13)C magnetic resonance spectroscopy. Subjects with diet-controlled type 2 diabetes (n = 9) and age- and body mass index-matched nondiabetic controls (n = 9) were studied. Mean fasting gastrocnemius glycogen concentration was significantly lower in the diabetic group (57.1 +/- 3.6 vs. 68.9 +/- 4.1 mmol/l; P < 0.05). After the first meal, mean glycogen concentration in the control group rose significantly from basal (97.1 +/- 7.0 mmol/l at 240 min; P = 0.005). After the second meal, the high level of muscle glycogen concentration in the control group was maintained, with a further rise to 108.0 +/- 11.6 mmol/l by 480 min. In the diabetic group, the postprandial rise was markedly lower than that of the control group (65.9 +/- 5.2 mmol/l at 240 min, P < 0.005, and 70.8 +/- 6.7 mmol/l at 480 min, P = 0.01) despite considerably greater serum insulin levels (752.0 +/- 109.0 vs. 372.3 +/- 78.2 pmol/l at 300 min, P = 0.013). This was associated with a significantly greater postprandial hyperglycemia (10.8 +/- 1.3 vs. 5.3 +/- 0.2 mmol/l at 240 min, P < 0.005). Basal muscle glycogen concentration correlated inversely with fasting blood glucose (r = -0.55, P < 0.02) and fasting serum insulin (r = -0.57, P < 0.02). The increment in muscle glycogen correlated with initial increment in serum insulin only in the control group (r = 0.87, P < 0.002). This study quantitates for the first time the subnormal basal muscle glycogen concentration and the inadequate glycogen storage after meals in type 2 diabetes.

Assessment of a chemiluminescent universal probe for taxonomical and epidemiological investigations of Aeromonas sp isolates.

AIMS: To assess a chemiluminescent universal probe for taxonomical and epidemiological investigations of Aeromonas sp isolates. METHODS: Total DNA was extracted from 69 well characterised Aeromonas sp strains and digested with the restriction endonucleases Sma I or Pst I. Following electrophoresis, the resulting fragments were transferred to a nylon membrane where they were hybridised to a commercially available universal probe of 16S + 23S rRNA. The banding patterns (ribotypes) were made visible by enhanced chemiluminescence. RESULTS: Both restriction endonucleases produced heterogeneous ribotypes so that no allocation could be made to any of the control genospecies tested. For A hydrophila and A caviae, however, groups of strains (mostly from the same patient) could be identified by indistinguishable banding patterns. A relatively high proportion (36%) of A sobria strains were non-typable. CONCLUSIONS: Although this universal chemiluminescent probe is user friendly, it is unsuitable for taxonomical investigations of Aeromonas sp. It is useful in epidemiological studies of A hydrophila and A caviae, but is of less value for A sobria.