Central serous chorioretinopathy secondary to intramuscular testosterone therapy

Summary

A patient treated with intramuscular testosterone replacement therapy for primary hypogonadism developed blurred vision shortly after receiving his testosterone injection. The symptom resolved over subsequent weeks and recurred after his next injection. A diagnosis of central serous chorioretinopathy (CSR) was confirmed following ophthalmology review. A decision was made to change the patient's testosterone regime from this 12-weekly intramuscular injection to a daily topical testosterone gel, given the possibility that peak blood levels of testosterone following intramuscular injection were causing his ocular complaint. His CSR did not recur after this change in treatment. CSR secondary to testosterone therapy is a rare finding but has been reported previously in the literature.

Learning Points

Blurred vision in patients treated with testosterone replacement therapy (TRT) should prompt an ophthalmology review. The potential for reduced risk of central serous chorioretinopathy (CSR) with daily transdermal testosterone remains a matter of conjecture. CSR is a rare potential side effect of TRT.

Acute diabetic neuropathy following improved glycaemic control: a case series and review

SUMMARY

We present three cases of acute diabetic neuropathy and highlight a potentially underappreciated link between tightening of glycaemic control and acute neuropathies in patients with diabetes. Case 1: A 56-year-old male with poorly controlled type 2 diabetes (T2DM) was commenced on basal-bolus insulin. He presented 6 weeks later with a diffuse painful sensory neuropathy and postural hypotension. He was diagnosed with treatment-induced neuropathy (TIN, insulin neuritis) and obtained symptomatic relief from pregabalin. Case 2: A 67-year-old male with T2DM and chronic hyperglycaemia presented with left lower limb pain, weakness and weight loss shortly after achieving target glycaemia with oral anti-hyperglycaemics. Neurological examination and neuro-electrophysiological studies suggested diabetic lumbosacral radiculo-plexus neuropathy (DLPRN, diabetic amyotrophy). Pain and weakness resolved over time. Case 3: A 58-year-old male was admitted with blurred vision diplopia and complete ptosis of the right eye, with intact pupillary reflexes, shortly after intensification of glucose-lowering treatment with an SGLT2 inhibitor as adjunct to metformin. He was diagnosed with a pupil-sparing third nerve palsy secondary to diabetic mononeuritis which improved over time. While all three acute neuropathies have been previously well described, all are rare and require a high index of clinical suspicion as they are essentially a diagnosis of exclusion. Interestingly, all three of our cases are linked by the development of acute neuropathy following a significant improvement in glycaemic control. This phenomenon is well described in TIN, but not previously highlighted in other acute neuropathies.

LEARNING POINTS

A link between acute tightening of glycaemic control and acute neuropathies has not been well described in literature. Clinicians caring for patients with diabetes who develop otherwise unexplained neurologic symptoms following a tightening of glycaemic control should consider the possibility of an acute diabetic neuropathy. Early recognition of these neuropathies can obviate the need for detailed and expensive investigations and allow for early institution of appropriate pain-relieving medications.

Insulin degludec improves long-term glycaemic control similarly to insulin glargine but with fewer hypoglycaemic episodes in patients with advanced type 2 diabetes on basal-bolus insulin therapy

The aim of the present study was to compare the long-term safety and efficacy of insulin degludec with those of insulin glargine in patients with advanced type 2 diabetes (T2D) over 78 weeks (the 52-week main trial and a 26-week extension). Patients were randomized to once-daily insulin degludec or insulin glargine, with mealtime insulin aspart ± metformin ± pioglitazone, and titrated to pre-breakfast plasma glucose values of 3.9-4.9 mmol/l (70-88 mg/dl). After 78 weeks, the overall rate of hypoglycaemia was 24% lower (p = 0.011) and the rate of nocturnal hypoglycaemia was 31% lower (p = 0.016) with insulin degludec in the extension trial set, while both groups of patients achieved similar glycaemic control. Rates of adverse events and total insulin doses were similar for both groups in the safety analysis set. During 18 months of treatment, insulin degludec + mealtime insulin aspart ± oral antidiabetic drugs in patients with T2D improves glycaemic control similarly, but confers lower risks of overall and nocturnal hypoglycaemia than with insulin glargine treatment.

A silent myocardial infarction in the diabetes outpatient clinic: case report and review of the literature

Silent myocardial ischaemia (SMI), defined as objective evidence of myocardial ischaemia in the absence of symptoms, has important clinical implications for the patient with coronary artery disease. We present a dramatic case of SMI in a diabetes patient who attended annual review clinic with ST elevation myocardial infarction. His troponin was normal on admission but raised to 10.7 ng/ml (normal <0.5) when repeated the next day. His angiogram showed diffused coronary artery disease. We here discuss the implications of silent ischaemia for the patient and for the physician caring for patients with diabetes.

Barriers to exercise in obese patients with type 2 diabetes

BACKGROUND

Although regular exercise is a critical component of the management of type 2 diabetes, many patients do not meet their exercise targets. Lack of exercise is associated with obesity and adverse cardiovascular outcomes.

AIM

We aimed to assess exercise habits in obese Irish patients with type 2 diabetes to determine if patients are adhering to exercise guidelines and to identify perceived barriers to exercise in this group.

DESIGN

A cross-sectional study of obese patients with type 2 diabetes attending routine outpatient diabetes clinics at our institution, a public teaching hospital located on the outskirts of Dublin City.

METHODS

A total of 145 obese patients with type 2 diabetes were administered a questionnaire to evaluate exercise habits and perceived barriers to exercise. Anthropometric details were measured.

RESULTS

About 47.6% (n = 69) of patients exercised for <150 minutes per week (40% of males, 62% of females; P = 0.019) and these patients had a higher body mass index than those meeting targets (35 vs. 33.5 kg/m(2); P = 0.02). Perceived barriers to exercise were varied, with lack of time and physical discomfort being the most common. Reported barriers to exercise varied with age, gender and marital status.

CONCLUSION

This study highlights the challenges facing clinicians in improving exercise levels in patients, and the need to identify the specific barriers to exercise in the individual to improve health outcomes.

Interns as teachers of medical students: a pilot programme

BACKGROUND

In recent years, rising numbers of medical students and an increasingly demanding clinical workload has put pressures on the educational systems for medical students in the hospital. Bedside teaching remains central to education, but tutorial delivery by registrars, tutors and consultants has proven to be increasingly difficult with the greater numbers of students now in the undergraduate system.

AIMS

We have performed a pilot study to determine the feasibility of developing a Junior Tutor Programme, to assist in the delivery of tutorials to undergraduate medical students.

METHODS

This was designed and delivered by interns under the supervision of the academic staff in the Departments of Medicine and Surgery in Connolly Hospital. The programme was evaluated by a questionnaire filled in by the students anonymously.

RESULTS

A supervised programme of tutorials delivered by interns is a potentially useful way to ensure delivery of clinical teaching to undergraduate medical students.

Utilization of Frontal Assessment Battery and Executive Interview 25 in assessing for dysexecutive syndrome and its association with diabetes self-care in elderly patients with type 2 diabetes mellitus

AIMS

Executive function (EF) comprises a set of cognitive skills that controls the execution of complex activities. In the context of diabetes, this may include patients' self-monitoring and daily management of their condition. We compared two different measures of EF in a population of elderly patients with type 2 diabetes mellitus (T2DM) and studied its relationship with diabetes self-care.

METHODS

Fifty patients (34 males) had EF assessed using Frontal Assessment Battery (FAB) and Executive Interview 25 (EXIT25). Diabetes self-care was assessed using the Summary of Diabetes Self-Care Activities (SDSCA) scale. Haemoglobin A1c (HbA1c), lipid levels, blood pressure and diabetes duration were recorded.

RESULTS

The mean age of the patients was 67.0+/-7.5 years and mean duration of diabetes was 8.1+/-6.4 years. Mean HbA1c was 7.0+/-1.2%, and mean fasting plasma glucose, cholesterol and LDL-C were 7.0+/-1.7mM, 4.0+/-0.9mM and 2.1+/-0.7mM respectively. Mean EXIT25 score was 9.5+/-4.6 in the range of normal EF (14% had EXIT25 score>15, indicating impaired EF). Mean FAB score was 13.7+/-3.3 (48% having scores<15, indicating impaired EF), suggesting a degree of dysexecutive syndrome involving frontal lobe functions. EXIT25 score was inversely correlated with SDSCA (r=-0.3, p<0.05) but no significant correlation between FAB and SDSCA or HbA1c, diabetes duration, lipid levels and blood pressure with EXIT25, FAB or SDCSA was found.

CONCLUSION

A substantial proportion of elderly patients with T2DM may have dysexecutive syndrome and impairment in EF may impact on self-care in this group.

Efficacy and safety comparison between the DPP-4 inhibitor vildagliptin and the sulfonylurea gliclazide after two years of monotherapy in drug-naïve patients with type 2 diabetes

This report is part of the overall evaluation of using vildagliptin in the treatment of type 2 diabetes. Here the results of a multi-center, double-blind, randomized, active-controlled study designed to compare the efficacy and safety of two years of monotherapy with vildagliptin 50 mg bid and gliclazide up to 320 mg/day in drug-naïve patients with type 2 diabetes are reported. A total of 546 patients were randomized and approximately 74% of patients completed the study in each group. HbA (1c) values were slightly higher in the gliclazide group (HbA (1c) of 8.7+/-0.1% vs. 8.5+/-0.1% in the vildagliptin group). The mean reduction in HbA (1c) from baseline to Week 104 was -0.5% in the vildagliptin group and -0.6% in the gliclazide group. The associated 95% confidence interval (CI) for the between-group difference (0.13%) in mean change was (-0.06%, 0.33%). Thus, noninferiority based on an upper limit of the CI of 0.3% was not met. In the vildagliptin group, weight increased by 0.8+/-0.2 kg compared to 1.6+/-0.2 kg in the gliclazide group (p<0.01). Mild hypoglycemia was recorded in 0.7% of patients in the vildagliptin group and in 1.7% in the gliclazide group. Both drugs were well tolerated. In summary, vildagliptin monotherapy resulted in improved glycemic control in drug-naïve patients with type 2 diabetes. Although the hypothesis of noninferiority to gliclazide was not borne out statistically, the reductions in HbA (1c) were similar over a two year period and vildagliptin had significant benefits in terms of less weight gain and less hypoglycemia.

Prevalence of the metabolic syndrome in patients with diabetes mellitus

BACKGROUND

Metabolic syndrome (MetS) is a vascular risk factor with prevalence in the general population of 17-25%.

AIM

To determine the prevalence of MetS in patients with diabetes mellitus (DM).

METHODS

A total of 200 patients [18% type 1 (T1DM), 82% type 2 (T2DM)] attending for annual review were studied. Standard blood tests were requested. Blood pressure and waist circumference were measured. Adult Treatment Panel III (ATP III) criteria for diagnosis of MetS were applied.

RESULTS

A total of 122 (61%) patients had MetS. More patients with T2DM (69.5%) than TIDM (22.2%) had MetS. Despite treatment of DM (100%), hypertension (69.5%) and dyslipidaemia (48.3%), 114 patients (57%) still met the criteria for MetS at time of study.

CONCLUSIONS

Most T2DM patients have MetS but it is uncommon in T1DM. Despite treatment, almost half of patients still met the criteria for MetS. Aggressive treatment of MetS components is required to reduce cardiovascular risk in DM.

Once-daily insulin detemir in a cohort of insulin-naïve patients with type 2 diabetes: a sub-analysis from the PREDICTIVE study

OBJECTIVE

PREDICTIVE is a large, observational study of the empirical use of insulin detemir in patients with type 1 or type 2 diabetes (T1DM/T2DM). This post hoc analysis evaluates insulin-naïve patients with T2DM uncontrolled on oral antidiabetic drugs (OADs) who were initiated and remained on once-daily insulin detemir for 12 weeks.

RESEARCH DESIGN AND METHODS

This observational, multinational, multi-center, open-label prospective study evaluated the efficacy and safety of insulin detemir in 1653 insulin-naïve patients with T2DM (mean age 60.8 +/- 10.9 years, BMI 29.8 +/- 4.8 kg/m(2), and HbA(1C) 8.82 +/- 1.50%). Statistical comparisons were made between baseline and 12-week follow up data. Our study was subject to the usual limitations of observational studies.

MAIN OUTCOME MEASURES

Endpoints were: incidence of serious adverse drug reactions, including number of hypoglycemic events (total, major, and nocturnal), glycemic parameters, and weight change.

RESULTS

Following insulin initiation, no significant change occurred in the number of nocturnal hypoglycemic events or total hypoglycemic events (p = 0.4513), and no serious adverse drug reactions were observed during the 12 weeks of treatment. HbA(1C) decreased by a mean 1.25% (SD +/- 1.25%; p < 0.0001), with 30% of patients (n = 383) achieving HbA(1C) <7% at 12 weeks. Mean changes in fasting blood glucose and fasting blood glucose variability were -3.62 mmol/L (SD +/- 2.93; p < 0.0001) and -0.48 mmol/L (SD +/- 1.03; p < 0.0001), respectively. Body weight decreased by a mean 0.5 kg (SD +/- 3.3; p < 0.0001), with weight loss or no weight change occurring in a substantial percentage of patients in each BMI category (<25, 25-30, 30-35, and >35 kg/m(2)). Patients with higher baseline BMI lost the most weight, with the greatest weight loss (-1.20 kg) reported in those with BMI >35 kg/m(2).

CONCLUSIONS

Empirical use of insulin detemir as an insulin initiation strategy can improve glycemic control with good tolerability, including a low risk of hypoglycemia and a weight benefit, in a majority of insulin-naïve patients uncontrolled on OADs.

Switching from NPH insulin to once-daily insulin detemir in basal-bolus-treated patients with diabetes mellitus: data from the European cohort of the PREDICTIVE study

BACKGROUND

The PREDICTIVE study is a multinational observational study designed to follow up patients with diabetes who started insulin detemir (IDet) in routine care. Recruitment started in June 2004 and is ongoing in some countries.

METHODS

We report 12-week follow-up data for patients with type 1 (T1D) or type 2 diabetes (T2D) in the European cohort who, as part of basal-bolus therapy, switched from once- (qd) or twice-daily (bid) neutral protamine Hagedorn insulin (NPH) to qd IDet. End-points - evaluated from patients' records and diaries - were incidence of serious adverse drug reactions, glycaemic parameters, hypoglycaemia and weight change.

RESULTS

A total of 3637 patients were included, n = 1500 T1D [mean age 40.9 years, body mass index (BMI) 25.0 kg/m(2), glycosylated haemoglobin (HbA(1c)) 7.9%] and n = 2137 T2D (mean age 60.5 years, BMI 31.9 kg/m(2), HbA(1c) 8.0%). IDet was well tolerated. Lower overall, major and nocturnal rates of hypoglycaemia were observed in T1D and T2D patients switching from NPH to IDet (overall, T1D: 38.2-18.56 episodes/patient year, p < 0.001; T2D: 13.8-3.3 [corrected] episodes/patient year, p < 0.001). Switching from bid NPH to qd IDet resulted in significant 12-week reductions in HbA(1c) (T1D: -0.40%; T2D: -0.56%; both p < 0.001). Switching from qd NPH to qd IDet, resulted in HbA(1c) reductions of: T1D -0.52%; T2D -0.56%; both p < 0.001. Fasting blood glucose levels were also significantly reduced in patients with T1D or T2D. Overall mean weight changes were: T1D: 0.0 kg, T2D: -0.2 kg after 12 weeks.

CONCLUSION

In routine care, patients with T1D or T2D may be switched from NPH to IDet qd as part of a basal-bolus regimen.

ACTH-secreting bronchial carcinoid: a diagnostic and therapeutic challenge

OBJECTIVE

We describe a case of Cushing's syndrome due to ectopic ACTH secretion, where the only potential source on conventional imaging was a tiny benign-appearing lung nodule, which failed to take up radiolabelled octreotide.

DESIGN AND METHODS

To determine whether the patient might respond to therapeutic administration of octreotide, a test dose was given.

RESULTS

Compared to ACTH and cortisol levels on a control day, the levels following the test dose of octreotide were lower. Subsequent therapeutic administration of subcutaneous octreotide normalised urine free cortisol, with symptomatic improvement, pending evaluation for surgery. Eventual resection of the lung nodule resulted in cure of hypercortisolism. Histological examination of the resected specimen confirmed bronchial carcinoid staining positive for ACTH.

CONCLUSIONS

This is one of the few cases described where ectopic ACTH secretion secondary to bronchial carcinoid responded to somatostatin analogue therapy. The case was also unusual in that the tumour responded despite not taking up radiolabelled octreotide.

Insulin detemir improves glycaemic control without weight gain in insulin-naïve patients with type 2 diabetes: subgroup analysis from the PREDICTIVE study

OBJECTIVE

Predictable Results and Experience in Diabetes through Intensification and Control to Target: an International Variability Evaluation (PREDICTIVE) is a multi-national, open-label, prospective, observational study assessing the safety and efficacy of insulin detemir in clinical practice. This post hoc subanalysis evaluates insulin-naïve patients on oral antidiabetic drugs (OADs) who were initiated on insulin detemir as basal therapy (+/- OADs).

METHODS

The European cohort of the PREDICTIVE study currently includes 20,531 patients (12,981 with type 2 diabetes) who were prescribed insulin detemir and followed up for 12, 26 or 52 weeks. Here, we report data from a subgroup of 2377 OAD-treated, insulin-naïve type 2 diabetes patients for a mean follow-up of 14.4 weeks. Patients were prescribed insulin detemir as basal therapy (+/- OADs) by their physician, as part of routine clinical care. Results were reported in comparison with baseline observations.

RESULTS

One serious adverse drug reaction was reported, which was a major hypoglycaemic episode. Treatment with insulin detemir (+/- OADs) significantly reduced mean haemoglobin A(1c) (HbA(1c)) (-1.3%; p < 0.0001), fasting glucose (-3.7 mmol/l; p < 0.0001), and within-patient fasting glucose variability (-0.5 mmol/l; p < 0.0001). In the majority of patients (82%), these improvements in glycaemic control were achieved with once daily administration of insulin detemir. There was a small reduction in mean body weight (-0.7 kg; p < 0.0001), which was most apparent in patients with a higher body mass index (BMI) at baseline. A significant negative relationship between weight change and baseline BMI was observed (greater the BMI, greater the weight reduction). Multiple regression analysis showed that BMI and HbA(1c) at baseline, and change in HbA(1c), were all predictors for weight change (p < 0.0001 for all), with BMI being the strongest predictor.

CONCLUSIONS

Patients with type 2 diabetes naïve to insulin can be effectively treated with once-daily insulin detemir (+/- OADs) to achieve improved glycaemic control with no adverse effect on weight and a low risk of hypoglycaemia. These short-term results are consistent with the findings of clinical trials.

Transferring to insulin detemir from NPH insulin or insulin glargine in type 2 diabetes patients on basal-only therapy with oral antidiabetic drugs improves glycaemic control and reduces weight gain and risk of hypoglycaemia: 14-week follow-up data from PREDICTIVE

AIM

The aim of this study was to evaluate the safety and efficacy of insulin detemir in type 2 diabetes patients previously receiving NPH insulin (NPH group, n = 175) or insulin glargine (glargine group, n = 118) in combination with oral antidiabetic drugs (OADs).

METHODS

Patients were transferred to insulin detemir, while the OAD regimen and number of injections remained the same. The incidence of serious adverse drug reactions, including major hypoglycaemia, and haemoglobin A(1c) (HbA(1c)), fasting glucose, within-patient fasting glucose variability and body weight change were measured at 14 weeks.

RESULTS

Glycaemic control improved in both NPH (HbA(1c) = -0.2%, p < 0.05; fasting glucose -1.0 mmol/l, p < 0.0001) and glargine (HbA(1c) = -0.6%, p < 0.0001; fasting glucose -1.4 mmol/l, p < 0.0001) groups, including a reduction in fasting glucose variability (p < 0.01 for both). The incidence of total and nocturnal hypoglycaemia was reduced in both NPH and glargine groups. The incidence of major hypoglycaemia was low and did not change significantly during the follow-up period. Mean body weight was significantly reduced in the NPH (-0.7 kg, p < 0.01) and glargine (-0.5 kg, p < 0.05) groups.

CONCLUSIONS

These results indicate that in type 2 diabetes, transferring from other basal insulins to insulin detemir in combination with OADs was associated with improvements in glycaemic control, which were accompanied by a reduced risk of hypoglycaemia and a reduction in body weight.

Prevalence of anaemia in patients with diabetes mellitus

BACKGROUND

Anaemia is an increasingly recognised entity in patients with diabetes mellitus.

AIMS

We aimed to determine the prevalence of anaemia in our population of patients with diabetes, and to examine the factors associated with anaemia.

METHODS

The haemoglobin (Hb) levels in a consecutive series of patients attending for annual review of their diabetes over a three-month period were measured. Patients were classified as anaemic as per the WHO criteria.

RESULTS

During the period of study, 270 patients attended for review. Eleven per cent of males and 16% of females were anaemic. Seventy four per cent of anaemic patients had a serum creatinine <110micromol/l and 72% of anaemic patients had a calculated creatinine clearance of >60ml/min.

CONCLUSIONS

Anaemia was relatively common in patients attending for routine outpatient diabetes clinic review. The high prevalence of anaemia supports the routine screening for anaemia in the diabetes out-patient clinic, including in those without overt nephropathy.

PREDICTIVE- a global, prospective observational study to evaluate insulin detemir treatment in types 1 and 2 diabetes: baseline characteristics and predictors of hypoglycaemia from the European cohort

AIM

PREDICTIVEtrade mark (Predictable Results and Experience in Diabetes through Intensification and Control to Target: An International Variability Evaluation) is a large, multi-national, observational study assessing the safety and efficacy of insulin detemir. We report the study design, population characteristics and baseline observations, including cross-sectional analysis, from 19 911 patients with type 1 or 2 diabetes.

METHODS

Patients with type 1 or 2 diabetes requiring basal insulin are prescribed insulin detemir and followed up for 12-52 weeks. Data on demographics, haemoglobin A(1c) (HbA(1c)), fasting glucose, within-subject fasting glucose variability and weight are collected from patient records (and/or recall for hypoglycaemia). A negative binomial distribution model is used to assess the influence of predictive/confounding variables on hypoglycaemic episodes in insulin-treated patients at baseline. Multi-factorial analysis of covariance is used to evaluate the association of the variables with current body weight and within-subject fasting glucose variability.

RESULTS

Total hypoglycaemic episodes in the 4 weeks prior to study start were 47.5 per patient-year in patients with type 1 and 9.2 per patient-year in patients with type 2 diabetes. The frequency of hypoglycaemia in insulin-treated patients showed a significant, positive association with duration of diabetes, number of insulin injections and fasting glucose variability but was inversely related to HbA(1c), fasting glucose and body mass index. Weight showed a significant positive association with gender (male > female) and insulin dosage. Weight was also positively associated with fasting glucose variability in patients with type 1 diabetes, and age and number of injections in patients with type 2 diabetes.

CONCLUSIONS

These baseline data showed that, in addition to the established relationship with intensive treatment and HbA(1c), frequency of hypoglycaemia was positively associated with fasting glucose variability. Follow-up data from PREDICTIVE will provide insights on insulin detemir in diabetes management.

Safety and efficacy of insulin detemir in clinical practice: 14-week follow-up data from type 1 and type 2 diabetes patients in the PREDICTIVE European cohort

PREDICTIVE (Predictable Results and Experience in Diabetes through Intensification and Control to Target: An International Variability Evaluation) is a large, multi-national, open-label, prospective, observational study assessing the safety and efficacy of insulin detemir in clinical practice. A total of 20,531 patients with type 1 or 2 diabetes from 11 countries were prescribed insulin detemir and followed up after a mean of 14.4 weeks. The primary endpoint was incidence of serious adverse drug reactions (SADRs), including major hypoglycaemia. Secondary endpoints were: haemoglobin A(1c) (HbA(1c)), mean self-monitored fasting glucose, within-patient fasting glucose variability and body weight change. Two hundred and fourteen patients (1%) reported SADRs, including major hypoglycaemia. The incidence of major hypoglycaemic episodes was reduced from 3.0/patient-year at baseline to 0.7/patient-year at follow-up in type 1 patients (p < 0.0001), and from 0.8 to 0.1/patient-year in type 2 patients (p < 0.0001). Insulin detemir improved glycaemic control in type 1 and type 2 patients, with reductions in mean HbA(1c) (0.5% and 0.9%, respectively, p < 0.0001 for both), fasting glucose (1.7 and 2.6 mmol/l, p < 0.0001 for both) and within-patient fasting glucose variability (0.7 and 0.5 mmol/l, p < 0.0001 for both). There was a small decrease in mean body weight in both type 1 and 2 patients (-0.1 kg, p < 0.01 and -0.4 kg, p < 0.0001 respectively). Insulin detemir was used once- or twice-daily in 49% and 50% of type 1 patients, and 77% and 23% of type 2 diabetes patients, respectively. The 14-week observations from PREDICTIVE support clinical trial data showing that insulin detemir improves glycaemic control, with a lowered risk of hypoglycaemia and no weight gain.

Acromegaly secondary to growth hormone releasing hormone secretion

BACKGROUND

Acromegaly secondary to growth hormone releasing hormone (GHRH) secretion is exceptionally rare.

AIM

To report a case of acromegaly diagnosed in 1984 and assumed to be pituitary in origin. Sixteen years later, the cause was found to be a GHRH secreting neuroendocrine pancreatic tumour.

METHOD

A case report.

CONCLUSION

Although ectopic GHRH production is very rare, endocrinologists should be aware of this possibility in acromegaly patients if a pituitary tumour was not detected using pituitary imaging.

A case of resistance to thyroid hormone without mutation in the thyroid hormone receptor beta

BACKGROUND

Resistance to Thyroid Hormone (RTH) is a condition caused by tissue hyposensitivity to the effects of circulating thyroid hormone, and may be misdiagnosed as hyperthyroidism.

AIMS

We report the first case of RTH in an Irish patient highlighting the clinical features and the pathophysiological mechanism underlying the characteristic laboratory abnormalities found in the condition.

METHODS

We describe an isolated case of RTH initially misdiagnosed as hyperthyroidism, and detail the investigations which ultimately led to the correct diagnosis. Genetic screening of the thyroid hormone receptor beta gene was performed.

RESULTS

Thyroid function tests including T3 suppression test and TRH-stimulation test suggested a diagnosis of RTH. Genetic testing failed to demonstrate a mutation in the thyroid hormone receptor.

CONCLUSION

RTH is a rare inherited condition that may be misdiagnosed as hyperthyroidism. The case we describe most likely results from a de novo mutation in an as yet undiscovered gene. RTH should be considered in patients with elevated thyroid hormone levels and normal TSH so that unnecessary and potentially harmful treatment can be avoided.

Target blood pressure for patients with type 2 diabetes is difficult to achieve in the setting of a busy diabetes clinic

BACKGROUND

Target blood pressure control in patients with type 2 diabetes should be 130/85 mmHg or less; however, it is not clear how achievable this target is in clinical practice.

AIM

To assess the adequacy of blood pressure control in patients with type 2 diabetes attending a busy outpatient clinic.

METHODS

One hundred and eight patients with type 2 diabetes were assessed for the presence of hypertension using a cut-off value of 130/85 mmHg. Antihypertensive treatment and diabetic complications were evaluated.

RESULTS

Hypertension was present in 67% of patients, in whom 90% were receiving anti-hypertensive treatment. Forty-nine per cent of the treated patients achieved target blood pressure. Of the undertreated patients, 55% were on one antihypertensive agent, 30% were on two agents and 15% were on three or more agents. The corresponding figures for the adequately treated patients were 28%, 31% and 41%, respectively (p=0.03).

CONCLUSION

Adequate blood pressure control was underachieved in this patient group underlying the difficulty in treating blood pressure to target values in patients with type 2 diabetes in the setting of outpatient diabetes clinics. A more aggressive strategy, in particular the use of multiple antihypertensive agents should be adopted.

Effects of type-2 diabetes and troglitazone on the expression patterns of small intestinal sugar transporters and PPAR-gamma in the Zucker diabetic fatty rat

BACKGROUND/AIMS

We have used the Zucker diabetic fatty (ZDF) rat to study the effects of type-2 diabetes and troglitazone on the small intestinal mucosal mass, sugar transporters and the peroxisomal proliferator-activated receptor, PPAR-gamma.

METHODS

Age-matched ZDF and lean control (ZLC) rats were fed a standard chow or a troglitazone-enriched diet for 6 weeks. The mucosa of the small intestines were then extracted, weighed, and SGLT1, GLUT2, GLUT5 and PPAR-gamma mRNA expression levels assessed by Northern blotting. In the same animal groups, Western blotting and immunohistochemistry were used to study SGLT1, GLUT2 and GLUT5 protein expression levels and targeting.

RESULTS

The ZDF rat small intestinal mucosal mass was 60% greater than the ZLC rat. However, the expression levels of SGLT1, GLUT2, GLUT5 mRNA and protein, and PPAR-gamma mRNA in the ZDF and ZLC rats were the same. In addition, the targeting of brush-border GLUT5 and basolateral GLUT2 protein in the ZDF and ZLC rats were the same. Troglitazone treatment reduced SGLT1 mRNA and protein expression levels by 50% in ZDF and ZLC rats, but had no effect on mucosal mass or the expression levels of GLUT2 mRNA and protein, GLUT5 mRNA, and PPAR-gamma mRNA. The expression levels of GLUT5 protein in troglitazone-treated ZLC rats were unchanged when compared to untreated ZLC rats. However, GLUT5 protein expression levels in the troglitazone-treated ZDF rats were 50% below the untreated ZDF rats.

CONCLUSIONS

Hyperphagia and insulin are the chronic regulators of small intestinal mucosal mass and sugar transporter expression patterns, respectively. Furthermore, troglitazone suppresses SGLT1 expression at the transcriptional level and GLUT5 at the post-translational level, independent of changes in glycemia or PPAR-gamma gene expression.

Effects of troglitazone on substrate storage and utilization in insulin-resistant rats

Elevated serum and tissue lipid stores are associated with skeletal muscle insulin resistance and diminished glucose-stimulated insulin secretion, the hallmarks of type 2 diabetes. We studied the effects of 6-wk treatment with the insulin sensitizer troglitazone on substrate storage and utilization in lean control and Zucker diabetic fatty (ZDF) rats. Troglitazone prevented development of diabetes and lowered serum triglycerides (TG) in ZDF rats. Soleus muscle glycogen and TG content were elevated twofold in untreated ZDF rats, and both were normalized by troglitazone to lean control levels (P < 0.05). Troglitazone also normalized insulin-stimulated glucose uptake as well as basal and insulin-stimulated glycogen synthesis, implying increased skeletal muscle glycogen turnover. The proportion of active pyruvate dehydrogenase (PDH) in soleus muscle was reduced in ZDF relative to lean control rat muscle (16 +/- 2 vs. 21 +/- 2%) but was restored by troglitazone treatment (30 +/- 3%). Increased PDH activation was associated with a 70% increase in glucose oxidation. Muscle lipoprotein lipase activity was decreased by 35% in ZDF compared with lean control rats and was increased twofold by troglitazone. Palmitate oxidation and incorporation into TG were higher in ZDF relative to lean control rats but were unaffected by troglitazone treatment. Troglitazone decreased the incorporation of glucose into the acyl group of TG by 60% in ZDF rats. In summary, ZDF rats demonstrate increased skeletal muscle glycogen and TG stores, both of which were reduced by troglitazone treatment. Troglitazone appears to increase both glycogen and TG turnover in skeletal muscle. Normalization of PDH activity and decreased glucose incorporation into acyl TG may underlie the improvements in intracellular substrate utilization and energy stores, which lead to decreased serum TG and glucose.

Increased beta-cell proliferation and reduced mass before diabetes onset in the nonobese diabetic mouse

To determine whether loss of beta-cell mass and function in the NOD mouse occurs gradually, beginning after the onset of insulitis, or abruptly, just before the onset of overt diabetes, beta-cell mass and rates of beta-cell proliferation and insulin secretory responses from the perfused pancreas were measured in NOD and control NOD/Scid mice at 8-9, 13, and 18 weeks of age. Of the NOD mice, 11 and 70% had diabetes (fasting blood glucose >8.3 mmol/l) at 13 and 18 weeks of age, respectively. Beta-cell mass in 8-week-old NOD mice was 69% of control mice (P>0.05), but the rate of 5-bromo-2-deoxyuridine uptake was greater, suggesting a compensatory proliferative response to ongoing autoimmune beta-cell destruction. Despite an increase in the rate of beta-cell proliferation, beta-cell mass was significantly reduced by 42% in 13-week-old nondiabetic NOD mice and by 73% in 18-week-old diabetic NOD mice. Insulin secretory responses to glucose and arginine demonstrated reductions of similar magnitude. In 18-week-old diabetic NOD mice, insulin secretion was reduced to a greater degree than beta-cell mass, suggesting the presence of beta-cell dysfunction in addition to reduced mass. These results suggest that in the NOD mouse, beta-cell destruction begins soon after the onset of insulitis. Despite a compensatory beta-cell proliferative response, beta-cell mass progressively falls and is significantly reduced by 13 weeks despite normal blood glucose concentrations. Diabetes may be present when residual beta-cell mass represents 30% of control levels.

Defective pancreatic beta-cell glycolytic signaling in hepatocyte nuclear factor-1alpha-deficient mice

Mutations in the hepatocyte nuclear factor-1alpha (HNF-1alpha) gene cause maturity onset diabetes of the young type 3, a form of type 2 diabetes mellitus. In mice lacking the HNF-1alpha gene, insulin secretion and intracellular calcium ([Ca2+]i) responses were impaired following stimulation with nutrient secretagogues such as glucose and glyceraldehyde but normal with non-nutrient stimuli such as potassium chloride. Patch clamp recordings revealed ATP-sensitive K+ currents (KATP) in beta-cells that were insensitive to suppression by glucose but normally sensitive to ATP. Exposure to mitochondrial substrates suppressed KATP, elevated [Ca2+]i, and corrected the insulin secretion defect. NAD(P)H responses to glucose were substantially reduced, and inhibitors of glycolytic NADH generation reproduced the mutant phenotype in normal islets. Flux of glucose through glycolysis in islets from mutant mice was reduced, as a result of which ATP generation in response to glucose was impaired. We conclude that hepatocyte nuclear factor-1alpha diabetes results from defective beta-cell glycolytic signaling, which is potentially correctable using substrates that bypass the defect.

Defective insulin secretion in hepatocyte nuclear factor 1alpha-deficient mice

Mutations in the gene for the transcription factor hepatocyte nuclear factor (HNF) 1alpha cause maturity-onset diabetes of the young (MODY) 3, a form of diabetes that results from defects in insulin secretion. Since the nature of these defects has not been defined, we compared insulin secretory function in heterozygous [HNF-1alpha (+/-)] or homozygous [HNF-1alpha (-/-)] mice with null mutations in the HNF-1alpha gene with their wild-type littermates [HNF-1alpha (+/+)]. Blood glucose concentrations were similar in HNF-1alpha (+/+) and (+/-) mice (7.8+/-0.2 and 7.9+/-0.3 mM), but were significantly higher in the HNF-1alpha (-/-) mice (13.1+/-0.7 mM, P < 0.001). Insulin secretory responses to glucose and arginine in the perfused pancreas and perifused islets from HNF-1alpha (-/-) mice were < 15% of the values in the other two groups and were associated with similar reductions in intracellular Ca2+ responses. These defects were not due to a decrease in glucokinase or insulin gene transcription. beta cell mass adjusted for body weight was not reduced in the (-/-) animals, although pancreatic insulin content adjusted for pancreas weight was slightly lower (0.06+/-0.01 vs. 0.10+/-0.01 microg/mg, P < 0.01) than in the (+/+) animals. In summary, a null mutation in the HNF-1alpha gene in homozygous mice leads to diabetes due to alterations in the pathways that regulate beta cell responses to secretagogues including glucose and arginine. These results provide further evidence in support of a key role for HNF-1alpha in the maintenance of normal beta cell function.

Troglitazone action is independent of adipose tissue

We have investigated the antidiabetic action of troglitazone in aP2/DTA mice, whose white and brown fat was virtually eliminated by fat-specific expression of diphtheria toxin A chain. aP2/DTA mice had markedly suppressed serum leptin levels and were hyperphagic, but did not gain excess weight. aP2/DTA mice fed a control diet were hyperlipidemic, hyperglycemic, and had hyperinsulinemia indicative of insulin-resistant diabetes. Treatment with troglitazone alleviated the hyperglycemia, normalized the tolerance to intraperitoneally injected glucose, and significantly decreased elevated insulin levels. Troglitazone also markedly decreased the serum levels of cholesterol, triglycerides, and free fatty acids both in wild-type and aP2/DTA mice. The decrease in serum triglycerides in aP2/DTA mice was due to a marked reduction in VLDL- and LDL-associated triglyceride. In skeletal muscle, triglyceride levels were decreased in aP2/DTA mice compared with controls, but glycogen levels were increased. Troglitazone treatment decreased skeletal muscle, but not hepatic triglyceride and increased hepatic and muscle glycogen content in wild-type mice. Troglitazone decreased muscle glycogen content in aP2/DTA mice without affecting muscle triglyceride levels. The levels of peroxisomal proliferator-activated receptor gamma mRNA in liver increased slightly in aP2/DTA mice and were not changed by troglitazone treatment. The results demonstrate that insulin resistance and diabetes can occur in animals without significant adipose deposits. Furthermore, troglitazone can alter glucose and lipid metabolism independent of its effects on adipose tissue.

Thyroid dysfunction is not associated with alterations in serum leptin levels

To determine if serum leptin levels are affected by thyroid dysfunction, we measured its concentration in serum samples from 25 euthyroid controls and 25 subjects each with hypothyroidism and thyrotoxicosis collected over a 3-month period. Mean leptin levels in the euthyroid (24.1 +/- 8.3 microg/L), hypothyroid (22.7 +/- 7.0 microg/L) and thyrotoxic (23.3 +/- 4.3 microg/L) groups were not significantly different. Data were available to express leptin in terms of body mass index (BMI) in 11 euthyroid, and 6 untreated hypothyroid and thyrotoxic individuals. There was a significant positive correlation between BMI and leptin level (r = 0.60, p = .0002) for this subgroup, irrespective of their thyroid status. These data suggest that leptin levels are not affected by thyroid dysfunction.

Relative effects of inhaled corticosteroids on immunopathology and physiology in asthma: a controlled study

BACKGROUND

Although corticosteroids are recognised as the most efficacious treatment for bronchial asthma, their mode of action remains unclear. A placebo controlled trial was undertaken of the effect of inhaled corticosteroids on physiological and immmunopathological parameters in asthmatic patients in whom the correlations between these indices were tested after treatment.

METHODS

Sixteen patients (two women) with asthma entered a double blind, placebo controlled, parallel study during which they inhaled either budesonide 800 micrograms twice daily or matching placebo for six weeks. Spirometric parameters and bronchial reactivity to histamine and terbutaline were measured and endobronchial biopsy samples were taken before and after treatment. Patients recorded morning and evening flow rates during the treatment period. The biopsy samples were subjected to immunohistological analysis to determine the disposition of inflammatory cells within the bronchial wall.

RESULTS

Treatment with budesonide resulted in a significant improvement in the 25-75% forced expiratory flow (FEF25-75) from a mean of 133 l/min before treatment to 169 l/min after treatment, and in the morning peak expiratory flow rate (PEFR) from a mean of 384 l/min before treatment to 415 l/min after treatment. No changes were seen in the placebo group. Comparison between the changes in the immunopathological indices after six weeks of treatment with placebo or budesonide showed a significant reduction in the numbers of mast cells (0.5/unit area to 0.2/ unit area), activated eosinophils, and the expression of HLA-DR antigens (relative density -1.9 before to 1.02 after treatment) on inflammatory cells in response to treatment with budesonide. Although reductions in the numbers of other inflammatory cells within the bronchial wall were recorded using immunohistological analysis, these changes were not statistically significant. Significant correlations were found between changing immunological indices and lung physiology.

CONCLUSIONS

This controlled study shows that inhaled corticosteroids cause improvement in physiological and immunopathological parameters in patients with stable asthma that are not seen with placebo, and that cause and effect relationships may exist between these two measures of disease status.

Prevention of hyperglycemia in the Zucker diabetic fatty rat by treatment with metformin or troglitazone

To determine whether metformin or troglitazone can delay the onset of diabetes in the Zucker diabetic fatty (ZDF) rat, lean control, fatty, and ZDF rats received metformin, troglitazone, or no treatment from 6 to 12 wk of age. Glucose, insulin, triglyceride (TG), and free fatty acid (FFA) levels and glucose stimulated insulin secretion by the perfused pancreas were measured. Metformin-treated rats gained significantly less weight. Both drugs prevented hyperglycemia by 12 wk in diabetic rats and significantly reduced TG and FFA levels. Insulin secretion at low glucose was elevated in untreated fatty and diabetic animals, and the increment in diabetic animals produced by glucose perfusion was attenuated compared with lean and fatty rats. Both drugs reduced basal insulin secretion in fatty and diabetic rats and improved glucose responsiveness in diabetic rats. Metformin and troglitazone delay the onset of diabetes in the ZDF rat. The significantly improved insulin secretory response of the pancreas undoubtedly contributes to the improved glucose tolerance.

Immunological/physiological relationships in asthma: potential regulation by lung macrophages

There is now a consensus that T-cell-mediated inflammation and eosinophil activation in the bronchial wall contribute to the pathogenesis of asthma. However, the relationship between these immunopathological mechanisms and the observed physiological aberrations remain unclear. Here, Len Poulter and colleagues identify the links between T-cell-mediated inflammation and bronchial hyperresponsiveness, and propose a hypothesis for asthma pathogenesis in which the combination of immunological and physiological abnormalities may result in the promotion of disease. Furthermore, they suggest that an integral factor in the prevention of this process is the regulation of bronchial T-cell reactivity by a population of immunosuppressive macrophages.

T-cell and macrophage subsets in the bronchial wall of clinically healthy subjects

This study was conducted to obtain quantitative data on the numbers of T-cells and macrophage subsets in the normal bronchial wall of man, and, thus, produce a baseline against which the numbers of these cells present in inflamed bronchi may be judged. Bronchial biopsies were obtained from 27 clinically healthy subjects attending hospital for elective orthopaedic operations. Eight of the subjects were smokers (median 3.5 pack-years), and eight were atopic as defined by skin prick test. Three to eight weeks after biopsy, subjects attended the lung function laboratory for spirometric testing and determination of provocative concentration of histamine producing a 20% fall in forced expiratory volume in one second (PC20FEV1). The bronchial biopsies were frozen and cryostat sections prepared. These sections were investigated with immunohistological techniques to reveal the presence and distribution of T-cell and macrophage subsets. Twenty six out of 27 subjects had spirometric values within the normal range, but a wide spectrum of bronchial reactivity was observed (PC20FEV1 range 2-36 mg histamine). Using monoclonal antibodies in immunohistological techniques, only small numbers of T-cells were seen, the majority being CD8+ cells in the epithelium. In the underlying tissue, CD4+ cells predominated (CD4/CD8 ratio, epithelium 1:9; underlying tissue 4:1). In both cases, approx. 50% of T-cells expressed the CD45Ro isotype. Small numbers of macrophages were observed in all samples. The majority of these cells expressed a "suppressor cell" phenotype (RFD1+RFD7+), whilst only a small proportion (median 11% ) exhibited the phenotype of antigen presenting cells (RFD1+RFD7-).(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of immunocompetent cells in the bronchial wall of clinically healthy subjects showing bronchial hyperresponsiveness

BACKGROUND

Nearly all asthmatic subjects show bronchial hyperresponsiveness, in that the provocative concentration of histamine reducing forced expiratory volume in one second (FEV1) by 20% (PC20FEV1) is < or = 8 mg/ml histamine, and have underlying chronic inflammation of the bronchial wall mediated by T cells. The possible cause and effect relationship between these phenomena remains an enigma. As a proportion of clinically healthy subjects show bronchial hyperresponsiveness, this study was undertaken to determine whether they also show evidence of bronchial inflammation.

METHODS

Bronchial biopsy specimens were obtained from 27 clinically healthy subjects with no history of lung disease. Samples were taken perioperatively before elective knee arthroscopy for sports injuries. Specimens were frozen and cryostat sections analysed immunocytochemically with monoclonal antibodies to identify the presence of T lymphocytes, antigen presenting cells, and the expression of HLA-DR. Double immunofluorescence studies were performed with monoclonal antibodies RFD1 and RFD7 to show the relative proportions of RFD1+ RFD7- antigen presenting cells, RFD1- RFD7+ mature phagocytes, and RFD1+ RFD7+ suppressor macrophages. Histological stains were performed to show the presence of eosinophils and mast cells. Three to four weeks after bronchoscopy spirometry was performed on these subjects to record FEV1, forced vital capacity (FVC), FEV1/FVC, and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75). Bronchial hyperreactivity was recorded by determining PC20FEV1 to histamine.

RESULTS

Nine of the 27 subjects showed bronchial hyperresponsiveness as defined by a PC20FEV1 of < or = 8 mg/ml histamine. Segregated subjects with and without bronchial hyperresponsiveness showed no difference in spirometric results. Immunohistological analysis showed no evidence of inflammation in either group. Numbers of T cells, eosinophils, and mast cells were the same in both groups as was the expression of HLA-DR antigen. No neutrophils were observed in any tissues. Interestingly, reduced numbers of macrophages with the phenotype of antigen presenting cells (monoclonal antibodies RFD1+ RFD7-) were recorded in the subjects with bronchial hyperresponsiveness, who also had a significant increase in the proportion of RFD1+ RFD7+ suppressor macrophages.

CONCLUSIONS

Up to 30% of selected clinically healthy subjects may have a PC20FEV1 of < or = 8 mg/ml histamine. This physiological trait can exist in the absence of bronchial inflammation. This suggests that bronchial hyperresponsiveness as currently defined is not dependent on immunopathological changes in the bronchial wall and does not necessarily promote even subclinical inflammation.