Abnormal peripheral circulation in type 2 diabetic patients with normal ankle-brachial index associates with coronary atherosclerosis, large artery stiffness, and peripheral vascular resistance

Infrared Thermography Follow-Up After Lower Limb Revascularization

BACKGROUND

The purpose of this study was with a simple clinical setting to compare skin temperature changes in the feet before and after revascularization and to identify possible correlation between ankle brachial index (ABI) and toe pressure (TP) values and foot skin temperature patient with and without diabetes.

METHODS

Forty outpatient clinic patients were measured ABI, TP, and the skin temperature using infrared thermography (IRT) at the foot before and after revascularization. Patients in the revascularization group were divided into subgroups depending on whether they had diabetes or not and a wound or not.

RESULTS

There were clear correlation between increase of ABI and TP and increase of the mean skin temperature on the feet after revascularization. The temperature was higher and the temperature change was greater among patients with diabetes. Side-to-side temperature difference between the revascularized feet and contralateral feet decreased after treatment. The mean temperature was higher in the feet with wound whether patient had diabetes mellitus or not.

CONCLUSION

The simple, prompt, and noninvasive IRT procedure showed its potential as a follow-up tool among patients with diabetes or peripheral arterial disease and previous lower limb revascularization.

Compression Therapy Is Not Contraindicated in Diabetic Patients with Venous or Mixed Leg Ulcer

The aim of this study was to investigate if compression therapy (CT) can be safely applied in diabetic patients with Venous Leg Ulcers (VLU), even when a moderate arterial impairment (defined by an Ankle-Brachial Pressure Index 0.5–0.8) occurs as in mixed leg ulcers (MLU). Materials and methods: in one of our previous publications we compared the outcomes of two groups of patients with recalcitrant leg ulcers. Seventy-one patients were affected by mixed venous and arterial impairment and 109 by isolated venous disease. Both groups were treated by tailored inelastic CT (with compression pressure <40 mm Hg in patients with MLU and >60 mm Hg in patients with VLU) and ultrasound guided foam sclerotherapy (UGFS) of the superficial incompetent veins with the reflux directed to the ulcer bed. In the present sub analysis of the same patients we compared the healing time of 107 non-diabetic patients (NDP), 69 with VLU and 38 with MLU) with the healing time of 73 diabetic patients (DP), 40 with VLU and 33 with MLU. Results: Twenty-five patients were lost at follow up. The results refer to 155 patients who completed the treatment protocol. In the VLU group median healing time was 25 weeks for NDP and 28 weeks in DP (p = 0.09). In the MLU group median healing time was 27 weeks for NDP and 29 weeks for DP (p = −0.19). Conclusions: when providing leg ulcer treatment by means of tailored compression regimen and foam sclerotherapy for superficial venous refluxes, diabetes has only a minor or no effect on the healing time of recalcitrant VLU or MLU.

Infrared Thermography and Vascular Disorders in Diabetic Feet

AIM

Diabetes mellitus (DM) and related foot complications constitute a growing healthcare burden. Diabetes mellitus is associated with lower-limb amputation, but diabetic foot assessment is challenging. Here, we evaluated a novel noninvasive diagnostic method-infrared thermography (IRT) -assessing its diagnostic potential compared to conventional noninvasive measurements.

METHODS

This study included patients with DM (n = 118) and healthy controls (n = 93). All participants underwent ankle brachial index and toe pressure (TP) measurements, and IRT using a standardized protocol with temperature measurement at five foot areas.

RESULTS

Compared to controls, patients with DM generally had warmer feet and exhibited a significantly greater temperature difference between feet (P < .001). Mean temperatures were highest in patients with DM with neuroischemia, followed by neuropathy. Patients with DM with angiopathy showed the lowest mean temperature-similar to controls and noncomplicated diabetics. Mean temperatures at all measurement sites were significantly higher with abnormal TP (<50 mmHg) than normal TP (≥50 mmHg) (P < .001). Infrared thermography revealed differences between angiosome areas, subclinical infections, and plantar high-pressure areas.

CONCLUSION

Infrared thermography revealed local temperature differences in high-risk diabetic feet. Normal skin surface temperature varies between individuals, but in combination with other tools, IRT might be useful in clinical screening.

CLINICALTRIALS ID

14212016.

Lower sensitivity of ankle-brachial index measurements among people suffering with diabetes-associated vascular disorders: A systematic review

Diabetes mellitus is a systemic disease affecting microvascular and macrovascular systems and is considered as the strongest risk factor for peripheral arterial disease. Although the prevalence of the peripheral arterial disease is high among people living with diabetes, its severity is not accurately detected with the prevalent diagnostic methodologies. The ankle-brachial index measurement is a simple, objective, and reliable tool for diagnosis of peripheral arterial disease. However, it is of limited value in the diagnosis of peripheral arterial disease among diabetic patients due to its low sensitivity among diabetic individuals. Diabetes mellitus results in atherosclerosis and calcification of peripheral arterial walls leading to false normal ankle-brachial index values. Therefore, healthcare practitioners should be careful not to misinterpret ankle-brachial index results among diabetic patients. A literature search was conducted using the keywords “ankle-brachial index,” “interpretation,” “limitations,” “diabetic foot,” and “peripheral arterial disease” on different medical search engines. The results were manually scanned and then further reviewed to select the articles related to our topic of discussion. This article will review the use of ankle-brachial index measurement among diabetic patients, its limitations and its prognostic value. In Conclusion, Ankle-brachial index can be used for diagnosis of peripheral arterial disease with some precautions (e.g. raising the threshold of diagnosis or using the lowest systolic pressure value measured at the ankle) and can also be a prognostic indicator for cardiovascular morbidity and mortality.

Relationship between peripheral artery disease and combined albuminuria and low estimated glomerular filtration rate among elderly patients with type 2 diabetes mellitus

This study aimed at investigating the combined effects of albuminuria and reduced estimated glomerular filtration rate (eGFR) on peripheral artery disease (PAD) among elderly patients with diabetes. A total of 236 subjects were cross-classified into four groups according to the presence or absence of albuminuria (urinary albumin creatinine ratio (ACR) ≥ 30 mg/g) and low eGFR (<60 mL/min/1.73 m²). Cardiovascular risk factors and the ankle-brachial index (ABI) were also assessed. After multivariate adjustment using logistic regression analysis, the odds ratios (OR) for prevalent PAD related to albuminuria with preserved eGFR, normoalbuminuria with low eGFR and albuminuria with low eGFR compared to normoalbuminuria with preserved eGFR were 1.10 [95% confidence interval (CI) = 0.43-2.79], 3.14 (95% CI = 1.20-8.22) and 3.87 (95% CI = 1.72-8.72), respectively. In conclusion, in elderly patients with type 2 diabetes, both normoalbuminuria with low eGFR and albuminuria with low eGFR are associated independently with PAD.

Endovascular treatment of critical ischemia in the diabetic foot: new thresholds, new anatomies

This review discusses the role of endovascular treatment in diabetic patients with critical limb ischemia (CLI). Angioplasty of the femoropopliteal region achieves similar technical success and limb salvage rates in diabetic and nondiabetic patients. Angioplasty in as many as possible tibial vessels is accompanied by more complete and faster ulcer healing as well as better limb salvage rates compared to isolated tibial angioplasty. Targeted revascularization of a specific vessel responsible for the perfusion of a specific ulcerated area is a promising new approach: it replaces revascularization of the angiographically easiest-to-access tibial vessel, even if this is not directly responsible for the perfusion of the ulcerated area, by revascularization of area-specific vascular territories. In conclusion, the endovascular approach shows very high efficacy in ulcer healing for diabetic patients with CLI. Larger prospective studies are now needed to estimate the long-term results of this approach.

Exercise attenuates the premature cardiovascular aging effects of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2D) is an example of a disease process that results in decrements in function additional to those imposed by the inexorable 'primary aging' process. These decrements due to disease, rather than primary aging, can be termed 'secondary aging', and include the premature development (as early as adolescence) of asymptomatic preclinical cardiovascular abnormalities (e.g. endothelial dysfunction, arterial stiffness, diastolic dysfunction), as well as impaired exercise performance. These abnormalities are important, as they are associated with greater cardiovascular morbidity and mortality in people with and without T2D. A better understanding of the pathophysiology of secondary cardiovascular aging in people with T2D is warranted, and an evaluation of the benefits of existing treatments for these abnormalities is useful (e.g. exercise training). The focus of this review is to discuss the data relevant to the following key postulates: (a) T2D causes premature cardiovascular aging; (b) in contrast to primary cardiovascular aging, the premature cardiovascular aging of T2D may be modifiable with exercise. The exercise-focused perspective for this review is appropriate because impairments in exercise performance are markers of premature cardiovascular aging in T2D, and also because exercise training shows promise to attenuate some aspects of cardiovascular aging during the preclinical stage.

Peripheral microvascular response to muscle contraction is unaltered by early diabetes but decreases with age

Long-term or untreated diabetes leads to micro- and macrovascular complications. However, there are few tests to evaluate microvascular function. A postcontraction blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) technique was exploited to measure peripheral microvascular function in diabetics and healthy controls matched with respect to age, body mass index, and physical activity. Postcontraction BOLD microvascular response was measured following 1-s maximal isometric ankle dorsiflexion in individuals with diabetes mellitus type I [DMI, n = 15, age 33 ± 3 yr (means ± SE), median diabetes duration = 5.5 yr] and type II (DMII, n = 16, age 45 ± 2 yr, median duration = 2.4 yr); responses were compared with controls (CONI and CONII). Peripheral macrovascular function of the popliteal and tibial arteries was assessed during exercise hyperemia with phase contrast magnetic resonance angiography following repetitive exercise. There were no group differences as a result of diabetes in peripheral microvascular function (peak BOLD response: DMI = 2.04 ± 0.38% vs. CONI = 2.08 ± 0.48%; DMII = 0.93 ± 0.24% vs. CONII = 1.13 ± 0.24%; mean ± SE), but the BOLD response was significantly influenced by age (partial r = -0.384, P = 0.003), supporting its sensitivity as a measure of microvascular function. Eleven individuals had no microvascular BOLD response, including three diabetics with neuropathy and four controls with a family history of diabetes. There were no differences in peripheral macrovascular function between groups when assessing exercise hyperemia or the pulsitility and resistive indexes. Although the BOLD microvascular response was not impaired in early diabetes, these results encourage further investigation of muscle BOLD as it relates to peripheral microvascular health.

β2-microglobulin, a novel biomarker of peripheral arterial disease, independently predicts aortic stiffness in these patients

Arterial stiffness is a prominent feature of vascular ageing and strongly predicts cardiovascular and total mortality. The β2-microglobulin, (β2M) a newly identified biomarker of peripheral arterial disease (PAD), is related to renal insufficiency, inflammatory and neoplastic diseases, but may also play a role in vascular dysfunction. However, the relationship between arterial stiffness and β2M has not been previously studied in patients with atherosclerosis. In the present study we examined a possible association between β2M and arterial stiffness in patients with PAD and in healthy subjects. Plasma β2M levels and parameters of arterial stiffness such as aortic pulse wave velocity (aPWV) and augmentation index (AIx) were measured in 66 patients with PAD and in 66 apparently healthy subjects. Plasma levels of β2M, aPWV and AIx were significantly increased in patients with PAD compared with controls (1858.1 ± 472.8 vs 1554.5 ± 277.9 μg/L, p < 0.001; 9.9 ± 2.2 m/s vs 7.6 ± 1.6 m/s, p < 0.001; 28 ± 8 vs 14 ± 11%, p < 0.001; respectively). There existed significant correlation between aPWV and β2M for the patient group (R = 0.47; p < 0.001), but not for the controls (R = 0.14; p = 0.26). In multivariate analysis, β2M remained independently associated with aPWV, fetuin-A, age and glomerular filtration rate in patients (R(2) = 0.5, p < 0.001). We found no relationship between β2M and AIx in either group. We demonstrated that among patients with PAD elevated plasma β2M levels were associated with higher aortic stiffness irrespective of cardiovascular disease risk factors. These data suggest that β2M may influence the pathogenesis of aortic stiffness in atherosclerosis.

An assessment of peripheral vascular disease in patients with diabetic foot ulcer

BACKGROUND

Peripheral vascular disease (PVD) is a chronic limb ischaemia caused by atherosclerosis of the peripheral arteries. Diabetes mellitus is a risk factor for this disease. The most common symptom of PVD is muscle pain in the lower limbs on exercise. In diabetes, pain perception may be blunted by the presence of peripheral neuropathy. Therefore, a patient with diabetes and PVD is more likely to present with an ischaemic ulcer or gangrene than a patient without diabetes. The use of ankle-brachial-pressure index (ABI) in the clinic and bedside provide a measure of blood flow to the ankle. This could help early detection, initiate early therapy and may thus reduce the risk of critical limb ischaemia and limb loss.

OBJECTIVE

The purpose of this study is to evaluate the occurrence of peripheral vascular disease using ankle-brachial index in diabetic patients with and without foot ulcers and the risk factors associated with diabetic foot ulcer (DFU).

METHOD

This prospective study involved all type 2 DM patients with foot ulcer (DFU population) and those without foot ulcers (non-DFU population) seen in our hospital. Their demographic, clinical and laboratory parameters were noted and documented. Measurement of ABI was done using a portable hand held Doppler and ankle pressures<0.9 is suggestive of PVD.

RESULTS

A total of 74 patients were recruited. Males were 42 (56.8%) and females were 32 (43.2%). The mean age of the patients was 62.89±10.66 years and the duration of diabetes was 7.61±7.57 years. Forty-six (62.2%) presented with foot ulcer while 28 (37.8%) were without foot ulcer. Patients with PVD represented by ABI<0.9 was DFU 31(76.4%) while in non-DFU it was 10 (13.4%). Multivariant analysis of variables associated with DFU in those with ABI<0.9 showed correlation with tobacco use r=.235, p=0.044; duration of diabetes r=-.427; p=0.001; and systolic blood pressure r=-.301; p=0.009.

DISCUSSION

The occurrence of PVD determined by the absence of >2 pulses by palpation alone and using ABI was 25.7% and 55.4% respectively. This suggests that assessment by palpation is subjective while the use of Doppler is quantitative and more reliable. DFU patients with PVD showed a significant correlation with tobacco use, duration of diabetes and systolic blood pressure but not with dyslipidaemia.

CONCLUSION

This study shows that these patients had risk factors for PVD. The use of hand held Doppler will aid early diagnosis of critical limb at risk of loss and help to prevent and reduce the high rate of limb loss in our patients.

Use and utility of ankle brachial index in patients with diabetes

Ankle brachial index (ABI) is a simple method to screen peripheral arterial disease (PAD) and to evaluate cardiovascular (CV) prognosis in the general population. Measuring it requires a hand-held Doppler probe but it can be done also with an automatic device. ABI is an effective tool for clinical practice or clinical studies. However, in diabetic patients, it has some specific caveats. Sensitivity of the standard threshold of 0.9 appears to be lower in diabetic patients with complications. Moreover, highly frequent arterial medial calcifications in diabetes increase ABI. It has been demonstrated that measurements >1.3 are well correlated with both an increased prevalence of PAD and CV risk. Therefore, ABI thresholds of less than 0.9 and more than 1.3 are highly suspicious for PAD and high CV risk in diabetic patients. However, when there is concomitant clinical peripheral neuropathy or high risk of arterial calcification, the efficiency of ABI seems to be limited. In this case, other methods should be applied, toe pressure, in particular. Thus, the ABI could be used in patients with diabetes, but values should be interpreted with precision, according to the clinical situation.

Ankle brachial index screening for occult vascular disease is not useful in HIV-positive patients

Metabolic complications common to the HIV-positive population may increase the risk for cardiovascular disease. Asymptomatic peripheral arterial disease (PAD) is associated with increased cardiovascular risk. The ankle-brachial pressure index (ABI) is a screening tool commonly used for the detection of asymptomatic PAD. The prevalence of asymptomatic PAD based on ABI in HIV-positive patients is unknown. This study was cross-sectional in design and assessed PAD by measuring the systolic ABI as determined by a handheld 8-MHz Doppler probe with the patient at rest in a supine position. A brief medical history including pertinent risk factors was obtained. One hundred and sixty-seven HIV-positive patients were evaluated (97.6% male; mean age 52.0 years; 31.2% current smokers, 29.4% former smokers, 26.3% diabetes mellitus). Asymptomatic PAD (ABI < or = 0.9) was found in four patients (2.4%, 95% CI: 0.3-4.5%). Smoking was a significant predictor of PAD. Patients with a positive test for PAD had at least two major risk factors for the disease including smoking, a history of disease in another vascular bed, dyslipidemia, diabetes, and hypertension. All patients with a positive test for PAD had a high risk (>20%) for cardiovascular disease according to the Framingham risk score. Three of the four patients with positive tests had previously diagnosed vascular disease (CAD, stroke). Three patients presenting with PAD were evaluated and all had a positive ABI. The prevalence of PAD compared to previous studies on PAD in HIV was low and identified only those patients with high cardiovascular risk based on other features. ABI was not useful in detecting occult vascular disease in HIV-positive patients and offers no additional information to that derived from cardiovascular risk stratification.

Common Carotid Artery Intima-media Thickness is not Increased but Distensibility is Reduced in Normotensive Patients with Type 2 Diabetes compared with Control Subjects

This study evaluated carotid artery parameters in normotensive patients with type 2 diabetes compared with non-diabetic control subjects. Using a high-resolution B-mode ultrasound scanner, common carotid artery intima-media thickness (IMT) and carotid tree atheroma thickness were measured in 82 patients with type 2 diabetes and 41 controls. The distensibility of the common carotid artery was calculated using the Reneman equation. Distensibility was significantly decreased and atheroma thickness was significantly increased in the diabetes group. There was no significant difference in IMT between the two groups. Stepwise linear regression analysis revealed an association between common carotid artery distensibility and post-ischaemic dilatation of the brachial artery (a measure of endothelial function), body mass index and diabetes duration in patients with type 2 diabetes. In conclusion, common carotid artery IMT in normotensive patients with type 2 diabetes is comparable to that of control subjects, whereas atheroma thickness is higher and arterial stiffness more pronounced in those with type 2 diabetes, indicating the existence of atherosclerotic changes in normotensive type 2 diabetes patients.

Arterial stiffness in diabetes and the metabolic syndrome: a pathway to cardiovascular disease

Increased arterial stiffness associated with diabetes and the metabolic syndrome may in part explain the increased cardiovascular disease risk observed in these conditions. Arterial stiffness can be estimated by quantifying pulse pressure but is better described by distensibility and compliance coefficients, pulse wave velocity and wave reflection. The most common non-invasive methodologies used to quantify these estimates of arterial stiffness (e.g. ultrasonography and applanation tonometry) are also described. We then review and summarise the current data on the associations between diabetes, the metabolic syndrome and insulin resistance on the one hand and greater arterial stiffness on the other, and identify and discuss some unresolved issues such as differential stiffening of central vs peripheral arterial segments, the impact of sex, and the pathobiology of increased arterial stiffness in diabetes and the metabolic syndrome. Finally, some considerations with regard to treatment options are presented. At present the most powerful therapy available for reducing arterial stiffness is to vigorously treat hypertension using pharmacological agents. New pharmacological strategies to reduce arterial stiffness are likely to be especially relevant to individuals with diabetes.

Prospective assessment of lower-extremity peripheral arterial disease in diabetic patients using a novel automated optical device

A new optical device based on the photoplethysmograph (PPG) method and an innovative algorithm for the assessment of lower-extremity peripheral arterial disease was investigated prospectively in patients with type II diabetes. This new functional PPG (fPPG) technique uses a cuffless functional test to assess diabetic peripheral arterial disease without operator dependency and the incompressible arteries, issues associated with ankle brachial pressure index (ABPI) measurement. Diabetic patients (n = 24; 47 legs; age, 70 +/- 3 years) were recruited from the vascular clinic, and controls (n = 15; 30 legs; age, 66 +/- 5 years) were recruited from the orthopedic outpatient clinic. All underwent resting ABPI, fPPG, and duplex angiography (DA) as "gold standard." fPPG requires the placement of an optical probe on the toe for acquisition of pulsatile arterial perfusion for a period of 30 seconds with the leg in supine and raised at 45 degrees positions. The data were analyzed, and indices were generated by an automated computer system. In those with diabetes, fPPG correlated significantly with DA (r = -.68, P < .01) and ABPI (r = -.65, P < .01). We also found a significant correlation between ABPI and DA (r = .81, P < .01). The analysis of the receiver operator curve showed that optimum sensitivity and specificity for ABPI and fPPG were 80% and 93% and 83% and 71%, respectively, against DA. This method uses changes in pulsatile arterial blood volume using a simple cuffless functional test. The fPPG investigation period was much shorter (5 minutes) with independence of operator skills, whereas ABPI took longer (10-15 minutes) and required operator experience. Although the fPPG results are promising, further improvement (eg, by incorporation of functional skin color and temperature changes) is required to improve the sensitivity and specificity of the system.

Altered proximal aortic stiffness and endothelin plasma levels in diabetic patients with end-stage renal disease

Peripheral artery stiffness is altered in diabetic patients with end-stage renal disease (ESRD), whereas few data exist to confirm this trend for proximal aortic stiffness. The pulse wave velocity of the proximal aorta (PWVr) and of the carotid-to-femoral aortic segment (PWVcf) were determined by ultrasound imaging in 160 patients with ESRD (70 diabetic) and in 160 matched control subjects. Also, plasma levels of endothelin, homocysteine, and high-sensitivity C-reactive protein were determined in both groups. Patients with ESRD had increased pulse pressure, left ventricular (LV) end-diastolic diameter, LV mass index, PWVr, and PWVcf compared with control subjects (p < 0.05). Diabetic patients had increased LV mass index, PWVr, and PWVcf compared with nondiabetic patients with ESRD (p < 0.05). Endothelin levels exhibited a strong relation with PWVr (r = 0.32, p < 0.001) and PWVcf (r = 0.33, p < 0.001) measurements in ESRD patients. Multivariate linear regression analysis revealed that age, diabetes, and plasma levels of endothelin were major determinants of increased PWVr measurements in the total ESRD population. After adjustment for age, body surface area, time on dialysis, systolic blood pressure, history of hypertension, and plasma endothelin levels, diabetes was an independent factor associated with PWVr in ESRD subjects. Diabetic patients with ESRD had significantly increased proximal aortic stiffness and significantly altered plasma levels of endothelin as compared with the nondiabetic.

Low blood flow estimates in lower-leg arteries predict cardiovascular events in Japanese patients with type 2 diabetes with normal ankle-brachial indexes

OBJECTIVE

To examine the association of baseline measures in lower-leg arteries and conventional cardiovascular risk factors with the incidence of cardiovascular disease (CVD) events in type 2 diabetic patients with normal ankle-brachial indexes (ABIs) (>0.9).

RESEARCH DESIGN AND METHODS

We studied 129 type 2 diabetic patients and 35 age-matched nondiabetic subjects with no apparent CVD consecutively admitted to our hospital. At baseline, total flow volume and resistive index, as an index of vascular resistance, at the popliteal artery was evaluated using gated two-dimensional cine-mode phase-contrast magnetic resonance imaging. Patients were followed 4.8 +/- 1.5 years (range 3.0-8.2) or until their first event of CVD.

RESULTS

On follow-up, 16 patients developed primary CVD events. Patients with CVD had lower blood flow (P < 0.01) and higher vascular resistance (P < 0.05) than patients without CVD. When the patients were grouped into tertiles according to their levels of total flow volume (129.6-85.5, 85.3-63.3, and 62.7-23.8 ml/min), Kaplan-Meier analysis showed a higher probability of developing CVD events in patients in the lowest than in patients in the highest (P = 0.0199, log-rank test) tertile. Multivariate Cox proportional hazards analysis revealed that the lowest tertile for flow volume (hazard ratio [HR] 8.60, 95% CI 1.61-45.97, P = 0.012), hypertension (3.99, 1.12-14.25, P = 0.033), and smoking status (12.01, 1.21-119.28, P = 0.034) were significant independent predictors of CVD events.

CONCLUSIONS

We have demonstrated that low blood flow estimates in lower-leg arteries may be predictive for CVD events among Japanese patients with type 2 diabetes even though they have a normal ABI.

Pioglitazone prevents corporal veno-occlusive dysfunction in a rat model of type 2 diabetes mellitus

OBJECTIVE

To determine whether corporal veno-occlusive dysfunction (CVOD), corporal smooth muscle (SM) loss, fibrosis and oxidative stress occur in a rat model of type 2 diabetes, and whether these are counteracted by pioglitazone, as pioglitazone is vasculoprotective, and corporal SM is an extension of arterial SM.

MATERIALS AND METHODS

Male obese Zucker fa/fa rats were fed chow containing 0%, 0.001% or 0.02% pioglitazone for 2 or 5 months, using untreated lean Zucker and Fischer 344 rats as controls. Functional changes were determined by dynamic-infusion cavernosometry. Histological changes were assessed by histochemistry and immunohistochemistry followed by quantitative image analysis and/or quantitative Western blot.

RESULTS

CVOD was detected at 4.5 months of diabetes, accompanied by a lower corporal SM/collagen ratio, and increases in collagen, collagen III/I ratio, apoptotic index, and systemic and tissue oxidative stress. In the short-term treatment, high-dose pioglitazone normalized glycaemia and ameliorated fibrosis and oxidative stress, but induced CVOD, whereas the effects with the low dose were not significant. However, low-dose pioglitazone for 5 months corrected all alterations.

CONCLUSION

Type 2 diabetes in Zucker fa/fa rats was associated with penile corporal fibrosis, oxidative stress, and CVOD, which were ameliorated by long-term low-dose pioglitazone, suggesting that this drug might protect the SM, independently from its antidiabetic effect.