PubMed Health⌕ Search

Biomedical subjects

J H Ahroni

Publications and source records attributed to J H Ahroni.

At least 19 recordsLinked to original sources
PubMed2001

Tissue oxygenation and skin blood flow in the diabetic foot: responses to cutaneous warming.

We previously reported an unexpected statistically significant decline in the mean transcutaneous partial pressure of oxygen (TcPO2) with cutaneous warming from 37 degrees C to 44 degrees C on the plantar diabetic foot, as opposed to the expected increase seen at the dorsal sites. To elucidate this relationship we compared changes with cutaneous warming in TcPO2 and skin circulation measured by laser Doppler flowmetry on the right plantar foot surface of 20 consecutive subjects. Neuropathy by monofilament testing was present in 55% of the cases. Right dorsal foot TcPO2 increased with cutaneous warming from 37 degrees C to 44 degrees by a mean change of +43.6+/-20.7 mmHg (+/- standard deviation) in 95% of the cases. In 42% of cases right plantar first metatarsal head TcPO2 fell with warming from 37 degrees C to 44 degrees C by a mean change of -10.7+/-7.6 mmHg. In the remaining 58% of cases right plantar first metatarsal head TcPO2 rose by 6.8+/-6.3 mmHg. In 95% of cases right plantar great toe laser Doppler perfusion units (LDPU) increased with warming from 36 degrees C to 44 degrees C by a mean change of +50.4+/-37.1. Blood flow measured by laser Doppler flowmetry increased in 95% of the subjects with heating. The finding that blood flow was increased with warming contradicts the hypothesis that arterioles in the plantar great toe cannot vasodilate in response to thermal stimuli. This finding supports the hypothesis that the decline in TcPO2 with warming might be due to an increase in epidermal oxygen consumption that exceeds the increase in oxygen delivery due to increased blood flow. The pathological mechanisms behind microvascular dysfunction in skin microcirculation in the diabetic foot need further investigation.

Aged↗
PubMed2000

Diabetic bullae: 12 cases of a purportedly rare cutaneous disorder.

BACKGROUND: Spontaneous bullae are a characteristic type of skin lesion occurring in patients with diabetes mellitus. These diabetic bullae are considered to be a rare phenomenon; only about 100 cases have been described in the literature since the disorder was first reported 70 years ago. METHODS: We collected a series of patients with diabetic bullae who were referred to us at a Veterans Affairs Medical Center Clinic specializing in diabetic foot problems. We then reviewed the medical literature for similar cases and summarized the available information. RESULTS: We saw 12 patients with typical diabetic bullae over an 8-year period in our clinic. The clinical presentation and outcome of the lesions in these patients were similar to those in previously reported cases. The patients were mostly elderly, all but one had lesions located on the lower extremities, all had peripheral neuropathy, two had secondary staphylococcal infection of their bullae, and in all patients the lesions healed without scarring. Although most of the patients had had previous similar lesions, the diagnosis of diabetic bullae had not been previously reported in any of them. CONCLUSIONS: We have reviewed the clinical syndrome of diabetic bullae and presented brief clinical details of these cases; we offer several vignettes and photographs of these lesions to remind clinicians of what we believe is a not so rare cutaneous disorder.

Adult↗
PubMed1999

Clinical correlates of plantar pressure among diabetic veterans.

OBJECTIVE: To assess the relationship between diabetes characteristics, medical history, foot deformity, sensory neuropathy, and plantar foot pressure. RESEARCH DESIGN AND METHODS: There were 517 subjects from a cohort of diabetic veterans enrolled in a prospective study of risk factors for foot complications who contributed 1,017 limbs for study. We interviewed subjects to collect data on demographics, diabetes characteristics, and medical history. A research nurse practitioner performed a directed physical exam of the lower extremities, assessing foot deformities and including quantitative sensory testing with a 5.07 monofilament. In-shoe foot-pressure measurements were obtained with F-scan insoles on subjects wearing their own footwear while walking 10 m at their usual pace. RESULTS: In univariate analyses, significant associations were seen between at least one measure of plantar pressure and body mass, sex, race, age, insulin use, certain foot deformities, plantar callus, and sensory neuropathy. Diabetes duration, HbA1c, and history of foot ulcer or amputation were unrelated to plantar pressure. In multiple regression analyses, body mass measured as log (weight), insulin use, white race, male sex, plantar callus, and diabetes duration were significantly related to certain pressures. Foot deformities were related primarily to forefoot pressures. With high pressure at two or more sites defined as the outcome, only body mass remained statistically significant as a predictor of this outcome in a backwards elimination logistic regression model. CONCLUSIONS: High in-shoe plantar pressure in diabetic subjects can be predicted in part from readily available clinical characteristics. The mechanisms by which these characteristics may be related to plantar pressure require further study.

Aged↗
PubMed1999

Lower-extremity amputation in diabetes. The independent effects of peripheral vascular disease, sensory neuropathy, and foot ulcers.

OBJECTIVE: To identify risk factors for lower-extremity amputation (LEA) in individuals with diabetes and to estimate the incidence of LEA. RESEARCH DESIGN AND METHODS: This is a prospective study of 776 U.S. veterans in a general medicine clinic in Seattle, Washington. The outcome was first LEA during follow-up. Potential risk factors evaluated in proportional hazards models included, among others, peripheral vascular disease (PVD), sensory neuropathy, former LEA, foot deformities and ulcers, diabetes duration and treatment, and hyperglycemia. RESULTS: Associated with an increased risk for LEA were PVD defined as transcutaneous oxygen < or = 50 mmHg (relative risk [RR] = 3.0, 95% CI 1.3-7.1), insensitivity to monofilament testing (RR = 2.9, odds ratio = 1.1-7.8), lower-extremity ulcers (RR = 2.5, CI 1.1-5.4), former LEA, and treatment with insulin when controlling for duration of diabetes and other factors in the model. PVD defined as absent or diminished lower-extremity pulses or an ankle arm index < or = 0.8 was also associated with a significantly higher risk of LEA in separate models. Foot ulcers were associated with an increased ipsilateral risk of amputation. The age-adjusted incidence among men only for LEA standardized to the 1991 U.S. male diabetic population was 11.3/1,000 patient-years. CONCLUSIONS: This prospective study shows that peripheral sensory neuropathy, PVD, foot ulcers (particularly if they appear on the same side as the eventual LEA), former amputation, and treatment with insulin are independent risk factors for LEA in patients with diabetes.

Adult↗
PubMed1999

A prospective study of risk factors for diabetic foot ulcer. The Seattle Diabetic Foot Study.

OBJECTIVE: Little prospective research exists on risk factors for diabetic foot ulcer that considers the independent effects of multiple potential etiologic agents. We prospectively studied the effects of diabetes characteristics, foot deformity, behavioral factors, and neurovascular function on foot ulcer risk among 749 diabetic veterans with 1,483 lower limbs. RESEARCH DESIGN AND METHODS: Eligible subjects included all diabetic enrollees of a general internal medicine clinic without foot ulcer, of whom 83% agreed to participate. Baseline assessment included history and lower-limb physical examination, tests for sensory and autonomic neuropathy, and measurements of macro- and microvascular perfusion in the foot. Subjects were followed for the occurrence of a full thickness skin defect on the foot that took > 14 days to heal, with a mean follow-up of 3.7 years. RESULTS: Using stepwise Cox regression analysis, the following factors were independently related to foot ulcer risk: foot insensitivity to the 5.07 monofilament (relative risk [95% CI]) 2.2 (1.5-3.1), past history of amputation 2.8 (1.8-4.3) or foot ulcer 1.6 (1.2-2.3), insulin use 1.6 (1.1-2.2), Charcot deformity 3.5 (1.2-9.9), 15 mmHg higher dorsal foot transcutaneous PO2 0.8 (0.7-0.9), 20 kg higher body weight 1.2 (1.1-1.4), 0.3 higher ankle-arm index 0.8 (0.7-1.0), poor vision 1.9 (1.4-2.6), and 13 mmHg orthostatic blood pressure fall 1.2 (1.1-1.5). Higher ulcer risk was associated with hammer/claw toe deformity and history of laser photocoagulation in certain subgroups. Unrelated to foot ulcer risk in multivariate models were diabetes duration and type, race, smoking status, diabetes education, joint mobility, hallux blood pressure, and other foot deformities. CONCLUSIONS: Certain foot deformities, reduced skin oxygenation and foot perfusion, poor vision, greater body mass, and both sensory and autonomic neuropathy independently influence foot ulcer risk, thereby providing support for a multifactorial etiology for diabetic foot ulceration.

Amputation, Surgical↗
PubMed1998

Reliability of F-scan in-shoe measurements of plantar pressure.

Research by our group and others indicates that many amputations of the lower limb occur after foot ulceration in patients with diabetes. It has been proposed that diabetic foot ulcers are mainly caused by repetitive trauma in areas of high plantar pressure during walking. Recent technology permits in-shoe measurement of plantar pressure. We assessed the reliability of the F-Scan in-shoe system for measurement of plantar pressure (Tekscan Inc., Boston, MA) in 51 subjects from a cohort of 977 diabetic veterans enrolled in a prospective study of risk factors for foot ulceration and amputation (the Seattle Diabetic Foot Study). Subjects were tested twice, wearing their own shoes. We used the coefficient of variation (CV) and the intra-class correlation coefficient (ICC) to estimate the reliability of F-Scan measurements of pressure. Peak pressure over the metatarsal heads proved to have the best indices of reliability, with CVs of 0.150 and 0.155, and ICCs of 0.755 and 0.751. Coefficients of variation for the heel, whole foot, and hallux ranged from 0.148 to 0.240, with ICCs ranging from 0.493 to 0.832. By published standards, peak pressures over the metatarsal heads and right hallux met the criteria for excellent reliability. Our ICCs for high pressures under the foot, heel, metatarsal heads, and hallux, and for peak pressures under the heel and left hallux represented fair-to-good reliability. No F-Scan plantar measurements could be judged by these criteria as having poor reliability. This clinical study found that for elderly patients with diabetes who were wearing their own shoes and were tested on two different days with different insoles, the F-Scan insole system was generally reliable for measurements of high pressure and peak pressure.

Adult↗
PubMed1998

Diabetes education and the primary care provider.

The problems involved in developing a practical primary care model of individualized diabetes management are discussed. Even though the multidisciplinary team approach is the preferred delivery system for diabetes care, primary care providers who do not have access to a diabetes care team can work with diabetes educators who provide a comprehensive body of knowledge, attitudes, and self-management skills to help people with diabetes make a positive psychosocial adaptation to diabetes. The person with diabetes is the only one in a position to determine what is learned and what is ultimately practiced.

Diabetes Mellitus↗
PubMed1997

Diagnostic utility of the history and physical examination for peripheral vascular disease among patients with diabetes mellitus.

BACKGROUND: We assessed the value of the medical history and physical examination in the diagnosis of peripheral vascular disease in diabetic subjects. METHODS: We performed a cross-sectional study in 631 diabetic veteran enrollees of a general internal medicine clinic that compared data obtained from a history and clinical evaluation with the presence of severe peripheral vascular disease defined as an ankle-arm index (AAI) < or = 0.5 derived from Doppler blood pressure measurement. RESULTS: We identified 90 limbs with an AAI < or = 0.5. Results presented below apply to the right leg, but do not differ from the left. Diminished or absent foot peripheral pulses (sensitivity 65%, specificity 78%), venous filling time > 20 sec (sensitivity 22%, specificity 93.9%), age > 65 years (sensitivity 83%, specificity 54%), claudication symptoms in < 1 block (sensitivity 50%, specificity 87%), and patient reported history of physician diagnosed peripheral vascular disease (PVD) (sensitivity 80%, specificity 70%) had the largest positive (or smallest negative) likelihood ratios. Capillary refill time > 5 sec or foot characteristics (absent hair, blue/purple color, skin coolness, or atrophy) conveyed little diagnostic information. Individual factors did not change disease probability to a clinically important degree. A stepwise logistic regression model identified four factors significantly (p < 0.05) associated with low AAI: absent or diminished peripheral pulses, patient reported history of PVD, age, and venous filling time. Substitution of < 1 block claudication for PVD history in this model resulted in a small reduction in model accuracy. CONCLUSIONS: Many purportedly useful historical and exam findings need not be elicited in diabetic patients suspected of having severe peripheral vascular disease, since most information related to probability of this disorder may be obtained from patient age, self-reported history of physician diagnosed PVD (or < 1 block claudication), peripheral pulse palpation, and venous filling time.

Aged↗
PubMed1997

Prevalence of radiographic foot abnormalities in patients with diabetes.

Clinicians are increasingly aware that mechanical aspects of foot deformities, such as Charcot changes, clawtoes, bunion deformities, or cavus or planus foot deformities, might have an impact on the occurrence, potential healing, and recurrence of foot ulcers. We report the prevalence of plain radiographic changes and attempt to rate the severity of those deformities in the feet of 456 diabetic veteran medicine clinic enrollees. All 456 radiographs were reviewed by orthopaedic surgeons to specifically identify Charcot changes, presence of arterial calcification, dislocation of the lesser toe metatarsophalangeal joints, hallux interphalangeal joint dislocation, and radiographic evidence of previous surgery. Radiographs of 428 patients were taken while weight-bearing, and these were reviewed to quantify hallux valgus angles, intermetatarsal 1-2 angles, fifth metatarsal-proximal phalangeal angles, second metatarsal lengths, lateral talocalcaneal and talar-first metatarsal angles, and claw toe deformities. The prevalence of Charcot changes was 1.4% (six subjects), and all had radiographic evidence of midfoot Charcot changes. Other deformities, such as clawtoes, hallux valgus, lesser toe joint dislocations, and alterations in arch height, are more common in veterans with diabetes.

Adult↗
PubMed1997

Risk factors for diabetic peripheral sensory neuropathy. Results of the Seattle Prospective Diabetic Foot Study.

OBJECTIVE: To identify risk factors for diabetic lower-extremity peripheral sensory neuropathy prospectively in a cohort of U.S. veterans with diabetes. RESEARCH DESIGN AND METHODS: General medicine clinic outpatients with diabetes were followed prospectively for the development of insensitivity to the 5.07 monofilament on the foot. RESULTS: Of 775 subjects, 388 (50%) had neuropathy at baseline. Of the 387 subjects without neuropathy at baseline, 288 were followed up, and of these, 58 (20%) developed neuropathy. Multivariate logistic regression modeling of prevalent neuropathy controlling for sex and race revealed independent and significant associations with age, duration of diabetes, glycohemoglobin level, height, history of lower-extremity ulceration, callus, and edema; an independent and inverse correlation was noted with ankle-arm index. Risk factors for incident neuropathy in multivariate logistic regression included age, baseline glycohemoglobin level, height, history of ulcer, and CAGE screening instrument alcohol score; current smoking and albumin level were inversely associated with risk. CONCLUSIONS: Poorer glycemic control increases the risk of neuropathy and is amenable to intervention. Height and age directly increase risk of neuropathy and may help identify patients at risk. A proportion of neuropathy in diabetic veterans is probably due to or worsened by alcohol ingestion. Neuropathy was less common in current smokers than subjects not currently smoking.

Age Factors↗
PubMed1996

Predictors of transcutaneous oxygen tension in the lower limbs of diabetic subjects.

We examined neuropathy, ankle pressure index (API), and other factors as predictors of transcutaneous oxygen (TcPO2) in the lower limbs of 657 diabetic subjects. Eligible subjects underwent a clinical assessment that included three standard measures of autonomic neuropathy. TcPO2 measurements were performed at 37 degrees C and 44 degrees C at four lower limb locations. Associations between potential predictors and TcPO2 were tested using univariate and multivariate statistics. Mean TcPO2 at any site did not differ by presence of autonomic neuropathy at either temperature, except for a significantly lower value at 44 degrees C below the knee (56.5 versus 59.2 mmHg, p = 0.021). In multivariate analysis, autonomic neuropathy was significantly and independently related to leg 44 degrees C TcPO2 only (coefficient = -2.6734, p = 0.0182). Much stronger associations were seen between TcPO2 and age, ankle blood pressure, and relative body weight on the plantar foot; and between API, glycosylated haemoglobin, ankle blood pressure, and pedal oedema on the dorsal foot and leg. We conclude that factors related to lower limb TcPO2 vary depending on measurement site. Autonomic neuropathy is not an important determinant of TcPO2 in the feet of diabetic subjects. Although several predictors of TcPO2 were identified, most of the variance of this measurement remains unexplained.

Algorithms↗
PubMed1996

Increased mortality associated with diabetic foot ulcer.

The objective of this study was to evaluate the relationship between foot ulceration and short-term mortality in veterans of the American military services with diabetes mellitus. A total of 725 diabetic subjects participated in a prospective study of risk factors for lower extremity complications between 1990 and 1994. Mean follow-up was 691.8 days (+/-SD 339.9, range 28-1436 days). Subjects who died during follow-up (n = 72) had a similar mean duration of diabetes to those who survived (12.6 years vs 11.2), but their mean age was greater (65.9 years vs 63.2, p = 0.026). The relative risk (RR) of death was 2.39 (95% confidence interval (CI) 1.13 to 4.58) in the subjects who developed foot ulcer (n = 88) compared to those who did not. The risk of death for those with foot ulcer was 12.1 per 100 person-years of follow-up compared to 5.1 in those without foot ulcer. Cox regression analysis demonstrated a greater than two-fold increased risk of death in ulcerated subjects after adjustment for age; diabetes type, duration, and treatment; glycosylated hemoglobin level; history of lower extremity amputation; and cumulative pack years smoked. Higher ankle-arm index was significantly related to lower mortality risk, independent of foot ulcer occurrence. We conclude that foot ulcer and lower extremity vascular disease are related to a higher risk of death in diabetic subjects. The reasons for this excess mortality require further investigation.

Age Factors↗
PubMed1995

Paradoxical transcutaneous oxygen response to cutaneous warming on the plantar foot surface: a caution for interpretation of plantar foot TcPO2 measurements.

We examined the effect of cutaneous warming on the transcutaneous oxygen measurement (TcPO2) at standard locations below the knee, on the dorsal foot, on the plantar right great toe, and on the plantar surface under the second metatarsal head of 656 diabetic and 16 nondiabetic subjects. All subjects underwent a directed medical history, physical examination, and neurovascular lower extremity evaluation and assessment of autonomic neuropathy. Associations between autonomic neuropathy and TcPO2 were tested using two-way analysis of variance and multiple linear regression. An unexpected, statistically significant fall in TcPO2 occurred with cutaneous warming from 37 degrees C to 44 degrees C on the plantar great toe surface that did not differ by presence of autonomic neuropathy, or the presence of diabetes (mean change: -8.82 mmHG, 95% confidence interval [CI]: -7.70 to -9.93). The TcPO2 measured at the plantar metatarsal head site also fell with cutaneous warming from 37 degrees C to 44 degrees C (mean change: -9.67 mmHG, 95% CI: -7.75 to -11.59). As expected, the TcPO2 increased with cutaneous warming from 37 degrees C to 44 degrees C on the dorsal foot site (mean rise:= 35.61 mmHg, 95% CI: 34.18 to 37.04). The mean TcPO2 at any site did not differ by presence of autonomic neuropathy at either 37 degrees C or 44 degrees C. We conclude that cutaneous warming leads to a paradoxical fall in TcPO2 on the plantar foot surface that does not depend on the presence of autonomic neuropathy or diabetes. Caution in interpretation of ambient versus warmed plantar TcPO2 values is recommended.

Adult↗
PubMed1995

The independent contributions of diabetic neuropathy and vasculopathy in foot ulceration. How great are the risks?

OBJECTIVE: To describe the relative contributions of neurological and vascular abnormalities to the overall risk of diabetic foot ulceration. RESEARCH DESIGN AND METHODS: A case-control study of diabetic veterans from the Seattle Veterans Affairs Medical Center was conducted using data collected from 46 patients with diabetic foot ulcers and 322 control subjects. Neuropathy was determined by vibratory, monofilament, and tendon reflex testing. Macrovascular disease was measured by ankle-arm blood pressure index, and cutaneous perfusion was measured by transcutaneous oxygen tension (TcPO2) on the dorsal foot. A multivariate logistic regression model was used to adjust for confounding variables and to calculate the odds ratios (ORs) for each independent risk factor. RESULTS: Three variables were significant independent predictors of foot ulceration: absence of Achilles tendon reflexes (adjusted OR 6.48, 95% confidence interval [CI] 2.37-18.06), insensate to the 5.07 monofilament (adjusted OR 18.42, 95% CI 3.83-88.47), and TcPO2 < 30 mmHg (adjusted OR 57.87, 95% CI 5.08-658.96). Absent vibratory sensation and low ankle-arm blood pressure index were not significant independent risk factors. CONCLUSIONS: Both neuropathy and vasculopathy are strong independent risk factors for the development of diabetic foot ulcers. In our model, the strongest risk factor is impaired cutaneous oxygenation. However, in the clinical setting, sensory examination with a 5.07 monofilament probably remains the single most practical measure of risk assessment.

Age Factors↗
PubMed1994

The health and functional status of veterans with diabetes.

OBJECTIVE: To determine the extent of functional impairment among veterans with diabetes and investigate whether such functional impairment is associated with measures of glycemic control, sensory neuropathy, lower extremity macrovascular disease, or other comorbid conditions. RESEARCH DESIGN AND METHODS: A 20-item general health survey (SF-20) developed by the Medical Outcomes Study (MOS) Group, was administered to 577 subjects participating in a prospective study of risk factors for diabetic foot ulceration. Measures of glycemic control and neurovascular disease included GHb, sensory lower extremity neuropathy assessed by aesthesiometry, and segmental lower extremity doppler blood pressures. RESULTS: Veterans with diabetes have major decreases in all domains of functional status; 87% were in poor health in terms of physical functioning and 86% in terms of health perceptions. Those with advancing age, symptoms of neuropathy and claudication, and a medical history of complications associated with diabetes had significantly more impairment of health status than those without. GHb values did not correlate with functional status measures. Subjects with neuropathy had statistically significant functional impairment. Subjects with vasculopathy had only two significantly low health status measures. CONCLUSIONS: In summary, the findings from this survey reveal that veterans with diabetes have low functional status scores. The presence of symptoms and complications accounts for only part of the impairments experienced by this group.

Blood Glucose↗
PubMed1992

Immediate and long-term efficacy of systemic antibiotics for eradicating nasal colonization with Staphylococcus aureus.

The efficacy of nine antibiotics used in different nonrandomized regimens for eradicating nasal colonization with Staphylococcus aureus was investigated in 72 patients. Dicloxacillin, erythromycin and three cephalosporins had eradicated colonization in about 75% of cases at early follow-up (less than or equal to 20 days) and in less than or equal to 50% at late follow-up (greater than or equal to 20 days). Clindamycin had eradicated colonization in all 13 patients at both follow-up times. One of two patients was successfully treated with fleroxacin, as were three of five with enoxacin. Among 21 patients treated with ofloxacin, colonization was eradicated in 20 (95%) at early follow-up and in all six of those from whom late follow-up cultures were obtained. Thus, clindamycin and ofloxacin appear to be useful systemic antibiotics for eradicating nasal colonization with Staphylococcus aureus.

Adult↗
PubMed1991

Chronology and determinants of tissue repair in diabetic lower-extremity ulcers.

The natural history of tissue repair and the critical determinants of faulty healing of diabetic ulcers remain obscure despite recent advances in our knowledge of the cellular physiology of normal cutaneous healing. To characterize the chronology and identify important factors affecting healing, we applied an objective method to quantify the rate of wound healing of full-thickness lower-extremity ulcers in 46 diabetic outpatients who received local wound care under a standardized clinical protocol. The initial ulcer healing rate, eventual status of tissue repair, and definitive clinical outcome were not significantly associated with age; diabetes type, duration, or treatment; level or change in glycosylated hemoglobin; current smoking; presence of sensory neuropathy; ulcer location or class; initial infection; or frequency of recurrent infections. However, direct measures of local cutaneous perfusion, estimated by periwound measurements of transcutaneous O2 tension (TcPo2) and transcutaneous CO2 tension (TcPco2), were significantly associated with the initial rate of tissue repair (P = 0.003 and 0.005, respectively). The strong prediction of early healing by these parameters of local skin perfusion was independent from the effects of segmental Doppler arterial blood pressure at the dorsalis pedis, although eventual ulcer reepithelialization was significantly related to foot blood pressure and periwound TcPo2 and TcPco2. We conclude that periwound cutaneous perfusion is the critical physiological determinant of diabetic ulcer healing, indicating a 39-fold increased risk of early healing failure when the average periwound TcPo2 is less than 20 mmHg.

Adult↗