The health care status of the diabetic population as reflected by physician claims to a major insurer.

BACKGROUND: Conventional epidemiologic data suggest that diabetic patients use more health care resources than nondiabetic patients, yet overall health care use by diabetic individuals has never been fully quantitated. We took a new approach to this issue based on the actual economics of the provision of health care to diabetic insured individuals. METHODS: The claims records in the Mutual of Omaha Current Trends database, which contains information on more than 400,000 individuals, were surveyed to identify patients with diabetes and create the contrast population of nondiabetic patients by exclusion. International Classification of Diseases, Ninth Revision, Clinical Modification, codes and Physicians' Current Procedural Terminology, Fourth Edition, codes were used to determine all diagnoses recorded and all physician services rendered to the contrast populations. Age- and sex-adjusted comparisons were performed using Mantel-Haenszel procedures to determine an adjusted odds ratio (AOR). RESULTS: A total of 13,304 diabetic individuals and 388,053 nondiabetic individuals who received health care services from January 1, 1988, to January 1, 1989, were identified. Diabetic insured individuals constituted 3.1% of the overall insured population yet accounted for 8.3% of the charges (P < .01). Inpatient charges accounted for 81% of total diabetic charges but only 61.5% of total nondiabetic charges (P < .001). Diabetic insured individuals had twice as many physician office visits (AOR = 1.87; 95% confidence interval [CI], 1.79 to 1.96), with 2.5 times more physician hospital visits [AOR = 2.50; 95% CI, 2.27 to 2.75). However, the increases in physician care were not uniformly distributed across the diagnostic spectrum. The frequencies of well-established complications of diabetes, such as ischemic heart disease (AOR = 3.32; 95% CI, 3.12 to 3.53), peripheral vascular disease (AOR = 3.14; 95% CI, 2.79 to 3.53), and eye disease (AOR = 3.10; 95% CI, 2.94 to 3.27), were threefold higher in the diabetic group, with parallel increases in related medical services, such as cardiac catheterization (AOR = 3.02; 95% CI, 2.27 to 4.0), vascular surgery (AOR = 2.94; 95% CI, 2.64 to 3.27), and ophthalmologic procedures (AOR = 2.94; 95% CI, 2.72 to 3.18). In contrast, most diagnostic categories showed little or no increase. For example, the frequency of neoplasms (AOR = 1.11; 95% CI, 1.03 to 1.19) was minimally increased, and the associated procedural concomitants of therapeutic radiology (AOR = 0.81; 95% CI, 0.47 to 1.39) and chemotherapy (AOR = 0.98; 95% CI, 0.60 to 1.60) were not increased in the diabetic group. CONCLUSIONS: Our most important new finding is that diabetic patients have neither an elevated risk for a wide spectrum of diseases nor an increase in the receipt of physician services for diagnostic categories without increased risk, despite more frequent physician encounters. We provide real-world risk estimates that help in calculating the effect of offering specific insurance to diabetic individuals or including them in group health plans. The techniques we have developed to analyze computerized claims databases in this way may serve to better quantify the true impact of chronic diseases on the health care system.

The effect of increasing temperature on skin blood flow and red cell deformability.

Using laser Doppler techniques in nine healthy volunteers, we contrasted the effect of increasing local skin temperature at the elbow, a skin site with nutritive microvasculature, and the finger pulp, with predominantly arteriovenous anastomic (AVA) perfusion). We also assessed flow at the finger dorsum, with contributions of both types of microvasculature. In parallel with the laser Doppler studies, we determined the effect of increasing temperature on the red cell deformability of our subjects, using the new technique of Cell Transit Time Analysis (CTTA). Thermal stimulation produced very large increases in skin blood flow at all three sites tested. However, the magnitude and the pattern of increase were different at the three sites. At the finger pulp, there was a linear approximately threefold increase in flow as temperature increased from the basal level to 44 degrees C. At the elbow, basal flow was considerably lower than at the finger pulp and increased very slowly until skin temperature reached 38 degrees C. From that point, flow increased sharply, reaching tenfold the basal level at 44 degrees C. The thermally induced increase at the finger dorsum was intermediate between the other two sites, with a pattern resembling the elbow more than the finger pulp. These differences among the sites were attributable to substantially different patterns of change in the two components of flow, microvascular volume and velocity. At the finger pulp, there was very little increase in microvascular volume with increasing temperature. The curve was practically flat from basal temperature to 44 degrees C. In contrast, there was a linear increase in red blood cell velocity of about 300%. At the elbow, both microvascular volume and red blood cell velocity exhibited a parallel curvilinear pattern of equivalent increase, on the order of 300% for each. There was only a small increase in both parameters until the temperature reached 38 degrees, at which point there was a sharp increase in both. At the finger dorsum, the situation was intermediate, again resembling the elbow more than the finger pulp. Cell Transit Time Analysis revealed a progressive decrease in red cell transit time (TT), from 3.28 ms at 28 degrees C to 2.48 m at 44 degrees C, an overall change of 24%. The decrease in TT was accompanied by an increase in transit frequency, measured as counts s-1 (C s-1), from 3.1 to 5.3, an overall change of 71%. The changes in both TT and C/S were essentially linear.(ABSTRACT TRUNCATED AT 400 WORDS)

Thermally-induced cutaneous vasodilatation in aging.

A decrease in heat-induced cutaneous vasodilatation has been implicated as the cause of increased heat stress in the elderly. We used laser Doppler techniques to study the skin blood flow response to local heat in 82 healthy volunteers. There were 39 young volunteers, mean age 29 +/- 1, and 43 elderly volunteers, mean age 76 +/- 1. There was minimal difference in skin blood flow at 35 degrees C between the two groups. In contrast, skin blood flow at 44 degrees C was significantly lower in the older subjects at nutritively perfused sites, such as the knee and elbow. However, there was no difference between the young and old groups in skin blood flow at the finger or toe pulp, sites with primarily arteriovenous anastomotic (AVA) flow. In the older subjects, the two components of skin blood flow, microvascular volume (VOL) and red blood cell velocity (VEL), were both decreased at 44 degrees C at nutritive sites, but not at AVA sites. Regression analysis demonstrated a linear fall in blood flow, VOL, and VEL with advancing age at nutritive sites at 44 degrees C. We conclude that thermally-induced cutaneous blood flow is reduced in older persons at nutritive capillary sites, but not at AVA sites.

Diabetic cutaneous microangiopathy.

PURPOSE: To determine a potential relationship between skin blood flow changes and the duration of diabetes and the presence of other microvascular complications. PATIENTS AND METHODS: Skin blood flow was measured by laser Doppler techniques at the finger and toe pulps, areas of predominant arteriovenous anastomotic (AVA) flow, and on the finger and toe dorsums, which have a greater nutritive microvascular contribution, in 83 diabetic patients and 39 nondiabetic control subjects. The average duration of diabetes was 14 +/- 1 years. Thirty-four patients had retinopathy. Eighteen patients had proteinuria. Forty patients had definite signs and symptoms of neuropathy, whereas 11 had no detectable neuropathy. RESULTS: There was little difference between diabetic and nondiabetic skin blood flow at normal body temperatures. However, at an elevated skin temperature of 44 degrees C, significant reductions in skin blood flow versus control were demonstrated in the diabetic group. Skin blood flow at finger and toe dorsums showed a decrease as a function of the duration of diabetes. In contrast, there was little, if any, relationship between the duration of diabetes and skin blood flow at the finger and toe pulps. Diabetic patients with retinopathy had significantly lower blood flow at both finger and toe dorsums than those without retinopathy. Even excluding patients with recent onset of diabetes from the analysis, flows at finger (18.6 +/- 2.0 mL/min/100 g) and toe dorsums (11.2 +/- 1.4 mL/min/100 g) in the patients with retinopathy were significantly lower than in diabetic patients without retinopathy [finger: 28.6 +/- 2.7 mL/min/100 g (p < 0.01) and toe: 15.1 +/- 1.5 mL/min/100 g (p < 0.05)]. The presence of proteinuria was also associated with lower blood flow at the toe dorsum. There were no differences between patients with or without clinical diabetic neuropathy. At finger and toe pulps, there were no significant differences between diabetic patients with or without retinopathy, proteinuria, or neuropathy. CONCLUSIONS: There appears to be a diabetic cutaneous microangiopathy that coexists with diabetic retinal and renal microvascular disease. This process is expressed primarily at sites of nutritive microvasculature. The ability to use the skin as a model for diabetic microangiopathy would have great practical importance, both experimentally and in clinical practice.

Skin blood flow and current perception in pentoxifylline-treated diabetic neuropathy.

There are several anecdotal reports of improvement in diabetic sensory neuropathy following a course of pentoxifylline therapy. Pentoxifylline theoretically could improve skin blood flow, thus reducing ischemia at axonal endings. The authors used laser Doppler techniques to measure skin blood flow and measured sine wave current perception thresholds (CPTs) in pentoxifylline-treated diabetic patients with sensory neuropathy. Twenty-four patients completed a six-month course of treatment. These patients had a predominantly "stocking" neuropathy; all the major abnormalities on clinical, laser Doppler, and current perception testing were found on the lower extremity. Seventeen of the 24 patients reported symptomatic improvement. A careful, graded neurologic examination confirmed that improvement, with a decrease in symptom score on the lower extremity (SSDW) from a baseline of 5.0 +/- 0.7 to 3.5 +/- 0.7 (p < 0.01) and of physical score (PSDW) from baseline 22.0 +/- 2.0 to 16.0 +/- 1.9 (p < 0.01) after six months. On the lower extremity, there was an increase in laser Doppler measured flow score (FS) both at 35 degrees and at 44 degrees C. FSDW (35 degrees) increased from 10 +/- 2 to 14 +/- 3 at six months (p < 0.05). FSDW (44 degrees) increased from 58 +/- 5 to 77 +/- 7 at six months (p < 0.01). There was an improvement in sine wave current perception measured by current perception threshold score (TS). TSDW dropped from 150 +/- 32 to 84 +/- 28 at six months (p < 0.03). In patients with diabetic sensory neuropathy, pentoxifylline appears to improve skin blood flow. Current perception thresholds improve in tandem, corroborating improvement in clinical neurologic findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Current perception thresholds in ageing.

We studied 40 healthy elderly and 31 healthy young volunteers and 25 elderly diabetic and 37 young diabetic patients. All subjects received detailed neurological examinations focusing particularly on sensory symptom and physical evaluations. Standardized assessment of symptoms and physical testing of light touch, pain, vibratory and thermal sensation were performed at the hand, wrist, elbow, foot, ankle and knee. The total symptom score (SS) and the total physical score (PS) were defined by summing test scores at each site. Current perception threshold (CPT) testing using constant current sine wave alternating current was completed at the same anatomical sites. CPT findings did not differ significantly between young and old healthy subjects. Older diabetic patients had higher CPTs than younger diabetic patients, but the severity of clinical diabetic neuropathy was greater in the older group. CPTs correlated with the degree of clinical diabetic neuropathy (r = 0.47 with SS and r = 0.60 with PS) rather than with age (r = 0.12). We conclude that current perception does not decline with age. Nor does ageing by itself worsen CPT values in patients with neuropathy. CPT testing is easily performed, clinically applicable and the first objective sensory measure not affected by the process of ageing.

The laser Doppler analysis of posturally induced changes in skin blood flow at elevated temperatures.

Recently, it has become possible to use laser Doppler techniques to separately quantitate the two components of blood flow, microvascular volume and red blood cell velocity. We used these techniques in 21 normal volunteers to quantitate the effect of postural changes in skin blood flow and its components at 35 degrees C and at 44 degrees C. Postural skin blood flow changes have ben studied extensively at basal skin temperature, but not at elevated temperatures. We contrasted changes at sites with arteriovenous anastomotic (AVA) blood flow (toe and finger pulps) with changes at sites with primarily nutritive flow (elbow and knee). Skin blood flow increased markedly with increasing temperature. The increases at the elbow and knee were the products of equivalent increases in both microvascular volume and velocity. In contrast, the increases on the finger and toe pulps were mainly due to increases in velocity. Elevation of both upper and lower extremities brought about a decrease in skin blood flow. Dependency increased blood flow. The magnitudes of observed changes were greater on the lower extremity than on the upper extremity and greater at 44 degrees C than at 35 degrees C. Once again, with postural change, the nutritive areas exhibited similar changes in volume and velocity while the AVA areas primarily showed velocity alterations. The correlation of systolic pulse pressures with blood flow was greater at the AVA areas than at nutritive areas and greater at 44 degrees C than at 35 degrees C. This correlation was with the velocity rather than with the volume component.(ABSTRACT TRUNCATED AT 250 WORDS)