Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
1.
Diabet Med ; 37(2): 286-297, 2020 02.
Article in English | MEDLINE | ID: mdl-31505051

ABSTRACT

AIMS: The Microalbuminuria Education Medication and Optimisation (MEMO) study, revealed improved cardiovascular risk and glycaemic control with 18 months of intensive multifactorial intervention in high-risk people with type 2 diabetes, without any increase in severe hypoglycaemia. Our aim was to assess longer-term outcomes at 4-year follow-up in these participants. METHODS: Some 189 individuals with type 2 diabetes and microalbuminuria were recruited from a multi-ethnic population in Leicestershire, UK. The intervention group (n = 95) received multifactorial intervention with self-management education, and the control group (n = 94) received usual care. The primary outcome was change in HbA1c , and secondary outcomes were blood pressure (BP), cholesterol, microalbuminuria, estimated GFR, cardiovascular risk scores and major adverse cardiovascular events. RESULTS: Some 130 participants (68.7%), mean (sd) age 60.8 (10.4) years, duration of diabetes 11.5 (9.7) years, completed 4 years of follow-up. Mean change [95% confidence intervals (CI)] in HbA1c over 4 years was greater with intensive intervention compared with control (-3 mmol/mol, 95% CI -4.95,-1.11; -0.4%, 95% CI -0.67,-0.15; P = 0.002). Significant improvements over the 4 years were also seen in systolic BP (-7.3 mmHg, 95% CI -11.1, -3.5; P < 0.001), diastolic BP (-2.9 mmHg, 95% CI -5.4, -0.3; P = 0.026), cholesterol (-0.3 mmol/l, 95% CI -0.52,-0.12; P = 0.002), and 10-year coronary heart disease (-5.3, 95% CI -8.2,-2.3; P < 0.001) and stroke risk (-4.4, 95% CI -7.5, -1.3; P < 0.001). CONCLUSION: Multifactorial intervention with structured diabetes self-management education compared with usual diabetes care has benefits for cardio-metabolic risk factor profile. There was no increase in severe hypoglycaemia and cardiovascular mortality despite intensive glycaemic control, although the study was not powered to assess these outcomes.


Subject(s)
Albuminuria/metabolism , Diabetes Mellitus, Type 2/therapy , Patient Education as Topic , Self-Management/methods , Aged , Albuminuria/complications , Albuminuria/etiology , Anticholesteremic Agents/therapeutic use , Antihypertensive Agents/therapeutic use , Blood Glucose/metabolism , Blood Pressure , Cardiovascular Diseases/mortality , Cholesterol/metabolism , Cholesterol, LDL/metabolism , Coronary Disease/epidemiology , Diabetes Mellitus, Type 2/metabolism , Diabetic Nephropathies , Female , Glomerular Filtration Rate , Glycated Hemoglobin/metabolism , Heart Disease Risk Factors , Humans , Hypercholesterolemia/complications , Hypercholesterolemia/drug therapy , Hypertension/complications , Hypertension/drug therapy , Hypoglycemia/chemically induced , Hypoglycemia/epidemiology , Hypoglycemic Agents/therapeutic use , Male , Middle Aged , Self-Management/education , Stroke/epidemiology , United Kingdom/epidemiology
2.
Postgrad Med J ; 87(1033): 763-8, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21873464

ABSTRACT

AIMS: To determine the prevalence of chronic disease comorbidity in south Asians (SAs) and white Europeans (WEs) with diabetes and to quantify the relationship of cardiac disease comorbidity (CDCM) and non-cardiac disease comorbidity (NCCM) to glycaemic control in SAs and WEs with type 1 and type 2 diabetes mellitus. METHODS: A cross-sectional study using a database of patients of SA (25.5%) and WE (74.5%) origin attending a specialist diabetes clinic in the UK between 2003 and 2005 (n=5664). RESULTS: The prevalence of SAs and WEs with type 1 diabetes was 12% and 88%, respectively; for those with type 2 diabetes the prevalence was 30% and 70%, respectively. Overall, the prevalence of comorbidity in people with type 1 diabetes was 25.5% and with type 2 diabetes was 47%. NCCM was more prevalent in WEs than SAs (17.6% vs 12.8%, p<0.001). In type 2 diabetes, the prevalence of suboptimal glycaemic control was significantly greater in SAs compared to WEs with NCCM and CDCM (79% vs 62%, p<0.001; 78% vs 65%, p<0.001, respectively). SAs with type 2 diabetes and comorbidity had excess odds of suboptimal glycaemic control compared to WEs: OR 2.27 (95% CI 1.50 to 3.43) for those with NCCM and OR 1.91 (95% CI 1.49 to 2.44) for those with CDCM. CONCLUSIONS: The prevalence of CDCM is higher in SAs compared to WEs with type 2 diabetes, whereas the prevalence of NCCM is higher in WEs compared to SAs. Taking into account comorbidities, SAs (compared to WEs) with type 2 diabetes had an excess risk of having HbA1c ≥7% ranging from 1.86- to 2.27-fold. Further research is needed to identify the reasons for unfavourable metabolic conditions in SAs and also develop and evaluate interventions.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 1/ethnology , Diabetes Mellitus, Type 2/ethnology , Heart Diseases/ethnology , Adult , Age Factors , Aged , Asian People , Comorbidity , Cross-Sectional Studies , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Female , Heart Diseases/blood , Humans , Male , Middle Aged , Risk Factors , Statistics, Nonparametric , Time Factors , United Kingdom/epidemiology , White People
3.
Diabetes Res Clin Pract ; 93(3): 328-36, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21640424

ABSTRACT

AIMS: To determine whether tighter cardiovascular risk factor control with structured education in individuals with type 2 diabetes (T2DM) and microalbuminuria benefits cardiovascular risk factors. METHODS: Participants from a multiethnic population, recruited from primary care and specialist clinics were randomised to intensive intervention with structured patient (DESMOND model) education (n=94) or usual care by own health professional (n=95). PRIMARY OUTCOME: change in HbA1c at 18months. SECONDARY OUTCOMES: changes in blood pressure (BP), cholesterol, albuminuria, proportion reaching risk factor targets, modelled cardiovascular risk scores. RESULTS: Mean (SD) age and diabetes duration of participants were 61.5 (10.5) and 11.5 (9.3) years, respectively. At 18months, intensive intervention showed significant improvements in HbA1c (7.1(1.0) vs. 7.8(1.4)%, p<0.0001), systolic BP (129(16) vs. 139(17) mmHg, p<0.0001), diastolic BP (70(11) vs. 76(12) mmHg, p<0.001), total cholesterol (3.7(0.8) vs. 4.1(0.9) mmol/l, p=0.001). Moderate and severe hypoglycaemia was 11.2 vs. 29.0%; p=0.001 and 0 vs. 6.3%; p=0.07, respectively. More intensive participants achieved ≥3 risk factor targets with greater reductions in cardiovascular risk scores. CONCLUSIONS: Intensive intervention showed greater improvements in metabolic control and cardiovascular risk profile with lower rates of moderate and severe hypoglycaemia. Intensive glycaemic interventions should be underpinned by structured education promoting self-management in T2DM.


Subject(s)
Albuminuria/drug therapy , Albuminuria/urine , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/urine , Adult , Aged , Aged, 80 and over , Albuminuria/blood , Antihypertensive Agents/therapeutic use , Aspirin/therapeutic use , Blood Pressure/drug effects , Cholesterol/blood , Diabetes Mellitus, Type 2/blood , Female , Glycated Hemoglobin/metabolism , Humans , Hypoglycemia/blood , Hypoglycemia/drug therapy , Hypoglycemia/urine , Hypoglycemic Agents/therapeutic use , Hypolipidemic Agents/therapeutic use , Insulin/therapeutic use , Male , Metformin/therapeutic use , Middle Aged , Risk Factors
4.
Postgrad Med J ; 85(1002): 219-22, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19417173

ABSTRACT

Some patients with type 2 diabetes mellitus (T2DM) are profoundly insulin resistant and require large insulin doses to achieve optimal glycaemic control. However, large volumes of subcutaneous conventional U-100 insulin can cause discomfort at the injection site, resulting in poor concordance with insulin therapy. One therapeutic option is the use of U-500 insulin, thus reducing the insulin volume by 80%. This review will address the practical issues associated with the use of U-500, clinical efficacy and safety aspects of this concentrated insulin, which has an important role in a subgroup of patients with T2DM.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/administration & dosage , Insulin Resistance/physiology , Insulin/administration & dosage , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/economics , Drug Costs , Humans , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/economics , Insulin/adverse effects , Insulin/economics , Obesity/complications , Patient Satisfaction , Treatment Outcome , Weight Gain
5.
Diabet Med ; 24(7): 714-9, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17403126

ABSTRACT

AIMS: To compare combination use of repaglinide, metformin and bedtime Neutral Protamine Hagedorn (NPH) insulin with conventional approaches of insulin initiation in patients with Type 2 diabetes (T2DM). METHODS: Eighty-two patients with T2DM with suboptimal glycaemic control on oral glucose-lowering agents were randomized to one of three treatment regimens for 4 months. Group 1 received metformin and twice daily biphasic 30/70 human insulin mixture (n = 27), group 2 metformin and bedtime NPH insulin (n = 26) and group 3 metformin, bedtime NPH insulin and mealtime repaglinide (n = 25). RESULTS: Seventy-five patients completed the study. Baseline and end-point mean HbA1c levels fell from 9.0 +/- 1.1 to 7.9 +/- 1.1% in group 1, 10.0 +/- 2.2 to 9.2 +/- 1.4% group 2 and 10.0 +/- 1.7 to 8.1 +/- 1.5% in group 3, respectively. All groups showed improvements in HbA1c. There was no significant difference between groups in the proportions of patients experiencing hypoglycaemia (29.6, 25.0 and 16.7%, respectively; P = 0.55) or in mean weight gain (2.9, 0.7 and 2.2 kg, respectively; P = 0.06). By 4 months, insulin doses were 0.63 +/- 0.32 IU/kg in group 1, 0.58 +/- 0.21 IU/kg in group 2 and 0.37 +/- 0.22 IU/kg in group 3 (group 3 vs. groups 1 and 2: P < 0.002). CONCLUSIONS: The approach using repaglinide, metformin and NPH insulin improved glycaemic control with a similar safety profile to conventional insulin initiation in T2DM and produced final glycaemic control similar to metformin and a twice daily biphasic insulin mixture.


Subject(s)
Carbamates/administration & dosage , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Insulin, Isophane/administration & dosage , Metformin/administration & dosage , Piperidines/administration & dosage , Adult , Aged , Aged, 80 and over , Drug Administration Schedule , Drug Therapy, Combination , Female , Humans , Hypoglycemia/chemically induced , Hypoglycemic Agents/adverse effects , Male , Middle Aged , Treatment Outcome , Weight Gain/physiology
6.
Diabetes Res Clin Pract ; 77(2): 215-22, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17141354

ABSTRACT

The aim of the study was to compare the efficacy of insulin glargine and aspart with NPH insulin and aspart in a basal bolus regimen in type 1 diabetes. In this 36-week randomised open-label two-period cross-over trial, subjects received 16 weeks' treatment with either once-daily insulin glargine or twice-daily NPH insulin after 4-week run-in. Primary outcome was HbA1c and secondary outcomes were fasting plasma glucose (FPG), weight change, incidence of hypoglycaemia, effect on lipid profile and patient satisfaction. Sixty patients with type 1 diabetes were recruited (33 male, mean age 42.7 years, mean HbA1c 8.53%) with 53 completing the study. At completion, HbA1c was lower with glargine and aspart than with NPH and aspart (8.07% versus 8.26%, difference -0.19 [95% CI 0.37-0.01]%, p=0.04). FPG was significantly different between glargine and NPH (p=0.002), with mean FPG on glargine 3mmol/L lower than on NPH at the end of the study. There were no differences in hypoglycaemia rate (p=0.63), weight (p=0.45) or lipid profile (p=0.18). Patient satisfaction was greater with glargine (DTSQ, p=0.001). Three patients discontinued as they wished to remain on glargine. We suggest that glargine combined with aspart is an effective basal bolus regimen in type 1 diabetes.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 1/drug therapy , Insulin, Isophane/therapeutic use , Insulin/analogs & derivatives , Adult , Blood Glucose/drug effects , Blood Pressure , Cholesterol/blood , Cross-Over Studies , Diabetes Mellitus, Type 1/blood , Drug Administration Schedule , Drug Therapy, Combination , Female , Glycated Hemoglobin/analysis , Humans , Hypoglycemic Agents/therapeutic use , Insulin/administration & dosage , Insulin/therapeutic use , Insulin Aspart , Insulin Glargine , Insulin, Isophane/administration & dosage , Insulin, Long-Acting , Male , Middle Aged
7.
Diabetes Metab Res Rev ; 23(4): 265-8, 2007 May.
Article in English | MEDLINE | ID: mdl-17109474

ABSTRACT

Some patients with type 2 diabetes mellitus (T2DM) have severe insulin resistance. Their insulin requirements are significantly greater. These patients need to take 2-3 injections at the same time to take the correct insulin dose or to redial the insulin pen. When daily insulin requirements are in excess of 300 units/day, the volume of the injected insulin becomes an issue. Large-volume injection can cause discomfort and lead to poor concordance with treatment. Using high-strength insulin e.g. U-500 insulin can reduce the volume of the injected insulin. Despite publications of small case reports or case series, no universal guidelines exist on the use of U-500 insulin. We discuss common sense approaches when considering the use of U-500 insulin in clinical practice.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/therapeutic use , Insulin/administration & dosage , Insulin/therapeutic use , Dose-Response Relationship, Drug , Drug Administration Schedule , Drug Costs , Hospitalization , Humans , Hypoglycemia/chemically induced , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/pharmacokinetics , Injections , Insulin/adverse effects , Insulin/pharmacokinetics , Professional Practice , Risk Assessment
10.
Diabet Med ; 18(S1): 1, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11168346
13.
Am J Kidney Dis ; 31(2): 313-9, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9469503

ABSTRACT

Sexual dysfunction remains a common and often distressing problem in the male dialysis population. Traditionally its management has consisted of correction of anemia, optimization of dialysis, removal of implicated medication, and finally depot injections of a testosterone ester. At a dedicated renal impotence clinic, we studied the effectiveness of testosterone replacement in men with biochemically proven hypogonadism and then vacuum tumescence therapy in those with continued erectile dysfunction. Depot testosterone was given to 27 patients (aged 52.4+/-2.5 years; duration of dialysis, 2.00+/-0.40 years; and duration of sexual dysfunction, 2.92+/-0.49 years): sexual function was fully restored in only three (11.1%), and two gradually lost the response over 18 months. Nineteen patients (70.3%) had partial responses, varying from an increased sense of well-being alone to restored sexual function apart from an impairment of the duration of penile erection. Five patients (18.5%) had no response, and testosterone was contraindicated in another four. Four of the treated patients (14.8%) reported fluid retention. Vacuum tumescence devices were then offered to 32 patients who remained impotent but declined by six. Twenty-six patients (aged 49.6+/-2.2 years; duration of dialysis, 2.50+/-0.58 years; and duration of sexual dysfunction, 3.26+/-0.56 years) used the devices, with 19 (73.1%) having full correction of their erectile dysfunction; six also continued with depot testosterone to maintain their libido. Penile discomfort was described by five patients (19.2%) whose potency was not restored. A further five predialysis patients have used the devices, and all had correction of their erectile dysfunction. The correction of biochemical hypogonadism in the male dialysis population with testosterone rarely restores sexual function to normal, whereas vacuum tumescence therapy corrects penile erection dysfunction in most patients.


Subject(s)
Equipment and Supplies , Erectile Dysfunction/therapy , Peritoneal Dialysis/adverse effects , Renal Dialysis/adverse effects , Testosterone/therapeutic use , Drug Implants , Erectile Dysfunction/etiology , Humans , Male , Middle Aged
14.
Nephrol Dial Transplant ; 12(4): 741-7, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9141005

ABSTRACT

BACKGROUND: Erythropoietin (rHuEpo) therapy has been shown to improve sexual function in the male dialysis population, with several studies suggesting a direct effect upon endocrine function, as well as correction of anaemia. Nevertheless many male dialysis patients receiving rHuEpo continue to complain of sexual dysfunction. METHODS: At a dedicated renal impotence clinic, 65 male dialysis patients were screened for endocrine disturbances. Baseline serum sex hormones were compared between those receiving and not receiving rHuEpo, using either the two-sample t test or the Mann-Whitney U test, after assessing for normality. Results from four patients were excluded on account of either medications (antiemetic phenothiazines), hepatic dysfunction, or carcinomatosis. RESULTS: Twenty-five patients (41.0%) were receiving rHuEpo, the recipients and non-recipients being well matched for haemoglobin (10.19 +/- 0.29 vs 10.55 +/- 0.25 g/dl, n.s.), age (51.1 +/- 1.9 vs 53.6 +/- 2.1 years, n.s.) and duration of sexual dysfunction (median, 3.0 vs 3.0 years, n.s.). The rHuEpo recipients had a higher median creatinine (1090 vs 972 micromol/l, P < 0.02), but similar nutritional status to the non-recipients (albumin 41.0 vs 39.0 g/l, n.s.). The total duration of rHuEpo therapy was 0.85 +/- 0.14 years. Prolactin levels were similar in both the rHuEpo recipients and non-recipients (440 vs 541 mu/l, n.s.), as were LH (11.0 vs 10.5 iu/l, n.s.) and FSH (8.0 vs 6.5 iu/l, n.s.). However, there were significant elevations of testosterone (19.8 +/- 1.3 vs 16.1 +/- 1.1 nmol/l, P < 0.05) and sex hormone binding globulin (SHBG) (40.5 vs 26.0 nmol/l, P < 0.01), with a trend toward elevated oestradiol (304 vs 248 pmol/l, P = 0.095) in the rHuEpo-treated group. Forty-eight subjects (78.7%) received peritoneal dialysis (PD), with the 19 rHuEpo recipients (39.6%) demonstrating increased serum testosterone (21.0 +/- 1.5 vs 16.6 +/- 1.3 nmol/l, P < 0.05), SHBG (40.5 vs 26.5 nmol/l, P < 0.01), LH (15.0 vs 10.0 iu/l, P < 0.01) and FSH (12.0 vs 5.3 iu/l, P < 0.05). These differences were not demonstrated in the 13 haemodialysis (HD) subjects. CONCLUSIONS: Male dialysis patients complaining of sexual dysfunction after correction of anaemia with rHuEpo are characterized by higher levels of serum testosterone and SHBG, but not suppression of hyperprolactinaemia or hyperoestrogenism. Male PD subjects receiving rHuEpo also demonstrated increased LH and FSH.


Subject(s)
Erythropoietin/adverse effects , Sexual Dysfunction, Physiological/etiology , Aged , Anemia/drug therapy , Anemia/etiology , Erectile Dysfunction/blood , Erectile Dysfunction/etiology , Estradiol/blood , Follicle Stimulating Hormone/blood , Humans , Kidney Failure, Chronic/complications , Kidney Failure, Chronic/drug therapy , Kidney Failure, Chronic/therapy , Luteinizing Hormone/blood , Male , Middle Aged , Peritoneal Dialysis/adverse effects , Peritoneal Dialysis, Continuous Ambulatory/adverse effects , Recombinant Proteins , Renal Dialysis/adverse effects , Sex Hormone-Binding Globulin/metabolism , Sexual Dysfunction, Physiological/blood , Testosterone/blood
15.
Diabet Med ; 14(1): 82-5, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9017359

ABSTRACT

Sudden death at night is known to occur in young patients with insulin-dependent (Type 1) diabetes mellitus (IDDM) but the aetiology is uncertain. A cardiac arrhythmia has been postulated, but there has been little evidence to support this. We present the case of a 31-year-old man with IDDM of 17 years duration, who died suddenly while asleep. Over preceding months, he had had strict glycaemic control (HbA1 8.9%), normal 24 h blood pressure (mean 131 +/- 2.1/76 +/- 2.2 mmHg), no evidence of microangiopathy or endothelial dysfunction and normal standard clinical tests of autonomic function. An electrocardiogram was similarly unremarkable, with a QTc interval of 0.414 s, and an echocardiogram had demonstrated normal left ventricular mass index (96.4 g m-2). However, there was no nocturnal dip in heart rate (daytime 74 +/- 2.7, and nocturnal 68 +/- 1.6 beats min-1), and he had grossly impaired baroreflex sensitivity during Phase 4 of the valsalva manoeuvre (0.5 ms mmHg-1), with power spectral analysis studies suggesting an abnormality of parasympathetic function. The coroner's autopsy demonstrated no structural abnormalities. We hypothesize that abnormal baroreflex sensitivity could either predict a risk of or account for some of the unexplained deaths in IDDM, in that relative overactivity of the sympathetic nervous system could cause ventricular arrhythmias.


Subject(s)
Baroreflex/physiology , Death, Sudden/etiology , Diabetes Mellitus, Type 1/mortality , Adult , Diabetes Mellitus, Type 1/physiopathology , Heart Rate/physiology , Humans , Male
16.
Br J Clin Pract ; 50(6): 346-8, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8983327

ABSTRACT

A 23-year-old man, previously fit and well, presented with an atypical pneumonia, associated with microangiopathic anaemia, thrombocytopenia, rhabdomyolysis and renal impairment. Despite administration of intravenous fluids and antibiotics, his condition rapidly deteriorated, and the possibility of an aggressive connective tissue disorder was raised. Thus he was treated with high-dose oral steroids and plasma exchange until autoantibodies were shown to be negative. At this stage it transpired that the patient had swallowed water from a stream three weeks earlier, and leptospira antibody titres were subsequently found to be elevated. Antibiotics were continued, and after a protracted course he made a full recovery. Leptospirosis should be remembered as a rare cause of atypical pneumonia, particularly if there is associated hepatic or renal impairment.


Subject(s)
Leptospira/isolation & purification , Leptospirosis/complications , Leptospirosis/diagnosis , Pneumonia/etiology , Adult , Enzyme-Linked Immunosorbent Assay , Humans , Male
17.
Acta Diabetol ; 33(2): 169-70, 1996 Jul.
Article in English | MEDLINE | ID: mdl-8870822

ABSTRACT

Diabetes mellitus increases the rate of atrioventricular block after a myocardial infarction; right bundle branch block is more common than expected in the diabetic outpatient population. We decided to assess whether diabetic subjects were more likely to need permanent cardiac pacemaker insertion. Data from patients in Leicestershire who had undergone permanent cardiac pacemaker insertion during a 4-year period were analysed. The capture recapture technique was used: Hospital Activity Analysis data as capture, ward admission book and case note confirmation as recapture. Diabetes coding accuracy was confirmed from the central register and from an analysis of 100 sets of case notes. The number of these patients with diabetes was then recorded. Data for the reference population was obtained using a survey of a market town in Leicestershire. There were 688 patients, most (79%) aged over 65 years. Our analysis was performed on this group. Of this age group undergoing pacemaker insertion. 11.1% was diabetic. In the same age group, 8.3% of the controls were diabetic: a relative risk of 1.34 (P < 0.01, 95% confidence interval 1.25-1.44). This relative risk is likely to be an underestimate. The aetiology of this excess risk is uncertain: it is most likely due to ischaemic heart disease, but microangiopathy or increased cholinergic sensitivity may play a role.


Subject(s)
Diabetes Mellitus/epidemiology , Pacemaker, Artificial , Adult , Aged , Female , Humans , Male , Middle Aged , Pacemaker, Artificial/statistics & numerical data , Risk Factors
18.
Br J Pharmacol ; 116(8): 3251-9, 1995 Dec.
Article in English | MEDLINE | ID: mdl-8719804

ABSTRACT

1. Previous studies have shown that endothelium-dependent relaxation in the aorta of spontaneously diabetic bio bred rats (BB) is impaired. 2. We have investigated noradrenaline (NA) contractility, endothelium-dependent acetylcholine (ACh) and bradykinin (BK) relaxation, and endothelium-independent sodium nitroprusside (SNP) relaxation in mesenteric resistance arteries of recent onset BB rats and established insulin treated BB rats, compared to their age-matched non diabetic controls. 3. There was no significant difference in the maximum contractile response or sensitivity to noradrenaline in either of the diabetic groups compared to their age-matched controls. 4. Incubation with the nitric oxide synthetase inhibitor NG-nitro-L-arginine (L-NOARG) resulted in a significant increase in maximum contractile response to noradrenaline in the recent onset age-matched control group (P < 0.05). Analysis of the whole dose-response curve (using ANOVA for repeated measures with paired t test) showed a significant left-ward shift following the addition of L-NOARG (P < 0.001). A similar but less marked shift (P < 0.01) was evident in vessels from recent onset diabetics. An overall shift in both sensitivity and maximum response was also evident in the age-matched non diabetic controls of the insulin-treated group (P < 0.05). However, by contrast, there was no significant change in sensitivity in the insulin-treated diabetic rats. 5. ACh-induced endothelium-dependent relaxation was significantly impaired in the recent onset diabetic rats compared to their age-matched controls (47 +/- 11% versus 92 +/- 2%, P < 0.05, n = 6), and in the insulin treated diabetic rats (34 +/- 5% versus 75 +/- 6%, P < 0.05, n = 6). The relaxation responses to BK also were significantly impaired in the diabetic rats compared to their age-matched controls (recent onset: 20 +/- 3% versus 72 +/- 7%, P < 0.05, n = 6; insulin treated: 12 +/- 9% versus 68 +/- 7%, P < 0.05, n = 7). 6. Incubation with either the nitric oxide synthetase substrate, U-arginine, or the free radical scavenging enzyme superoxide dismutase (150 mu ml-1) failed to improve the attenuated response of acetylcholine-induced relaxation in the diabetic vessels. 7. Endothelium-dependent relaxation mediated by ACh and BK was significantly attenuated in both the diabetic and control vessels after incubation with L-NOARG. 8. Pretreatment with a cyclo-oxygenase inhibitor, indomethacin, significantly enhanced the relaxation to ACh in both the recent onset and insulin treated diabetic rats (42 +/- 10%, n = 7 versus 64 +/- 7%, n = 7, P < 0.05, and 40 +/- 5%, n = 7 versus 65 +/- 9%, n = 6, P < 0.05). 9. Following endothelium removal, there was a marked impairment in endothelium-dependent relaxation responses to ACh and BK in both the diabetic and control vessels. 10. Incubation with the thromboxane A2 receptor antagonist SQ29548, did not significantly improve the ACh endothelium-dependent relaxation response in the diabetic vessels. 11. Endothelium-independent relaxation to sodium nitroprusside was significantly impaired in the first group of diabetic vessels studied; however, subsequent studies showed no impairment of the sodium nitroprusside response in the diabetic vessels. 12. In conclusion, the ability of the endothelium to regulate vascular contractility is reduced in recent onset diabetic vessels, and significantly impaired in established insulin treated diabetics. Relaxation to the endothelium-dependent vasodilators ACh and BK was impaired in both the recent onset and the established insulin treated diabetics, and the ACh response was significantly improved following pretreatment with indomethacin, suggesting a role for a cyclo-oxygenase-derived vasoconstrictor. Preliminary studies with a thromboxane A2, receptor antagonist, SQ29548 did not significantly improve the impaired relaxation to ACh, indicating that the vasoconstrictor prostanoid is not thromboxane A2.


Subject(s)
Acetylcholine/pharmacology , Adrenergic alpha-Agonists/pharmacology , Diabetes Mellitus, Type 1/physiopathology , Endothelium, Vascular/drug effects , Nitroprusside/pharmacology , Norepinephrine/pharmacology , Splanchnic Circulation/drug effects , Vasodilator Agents/pharmacology , Animals , Arginine/analogs & derivatives , Arginine/pharmacology , Bradykinin/pharmacology , Diabetes Mellitus, Type 1/drug therapy , Endothelium, Vascular/physiopathology , In Vitro Techniques , Insulin/administration & dosage , Microcirculation/drug effects , Nitric Oxide Synthase/antagonists & inhibitors , Nitroarginine , Rats , Rats, Inbred BB
SELECTION OF CITATIONS
SEARCH DETAIL
...