Albuquerque, NM, United States
Albuquerque, NM, United States
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Conway B.N.,Vanderbilt University | Aroda V.R.,MedStar Research Institute | Maynard J.D.,VeraLight | Matter N.,VeraLight | And 3 more authors.
Diabetes Care | Year: 2012

OBJECTIVE - Skin intrinsic fluorescence (SIF) reflects many factors, including the presence of certain advanced glycation end products. We investigated whether SIF was associated with coronary artery disease (CAD) in type 1 diabetes and whether this relationship was independent of renal disease. RESEARCH DESIGN AND METHODS - SIF was measured in 112 subjects from the Pittsburgh Epidemiology of Diabetes Complications (EDC) study and 60 from MedStar Health Research Institute when mean age and diabetes duration were 48 and 36 years, respectively. Cumulative glycemic exposure (updated mean A1C) represented a mean of 18 years' follow-up in EDC and 10.3 in MedStar. RESULTS - Of the 172 participants, 30 had CAD (15 male and 15 female). SIF levels were higher in those with CAD (P < 0.0001). SIF was strongly associated with CAD (odds ratio [OR] 3.5 [95% CI 2.1-6.1]). After age, duration, and updated mean A1C were controlled for, SIF remained associated with CAD (2.4 [1.3-4.4]), more strongly in men (5.6 [2.1-14.6]) than in women (1.4 [0.61-3.3]). As there was no significant sex interaction, further analyses were conducted combining the sexes. Further accounting for sex and nephropathy status did not improve the model fit, though with nephropathy in the model, the OR for SIF was reduced to 1.7 (95% CI 0.89-3.4). CONCLUSIONS - SIF has a significant cross-sectional association with CAD. This association is strongly linked to age and duration and, to a lesser degree, to mean A1C and renal disease. SIF therefore may be a useful overall marker of CAD risk in type 1 diabetes. © 2012 by the American Diabetes Association.


Tentolouris N.,National and Kapodistrian University of Athens | Lathouris P.,Social Insurance Institute | Lontou S.,National and Kapodistrian University of Athens | Tzemos K.,VeraLight | Maynard J.,VeraLight
Diabetes Research and Clinical Practice | Year: 2013

Background: We examined the accuracy of random capillary glucose (RCG) and two noninvasive screening methods, the ADA diabetes risk test (DRT) and skin fluorescence spectroscopy (SFS) as measured by Scout DS for detecting HbA1c-defined dysglycemia or type 2 diabetes in an at-risk cohort. Methods: Subjects were recruited at two clinical sites for a single non-fasting visit. Each subject had measurements of height, weight and waist circumference. A diabetes score was calculated from skin fluorescence measured on the left forearm. A finger prick was done to measure RCG and HbA1c (A1C). Health questionnaires were completed for the DRT. Increasing dysglycemia was defined as A1C ≥ 5.7% (39. mmol/mol) or ≥6.0% (42. mmol/mol). Type 2 diabetes was defined as A1C ≥ 6.5% (47.5. mmol/mol). Results: 398 of 409 subjects had complete data for analysis with means for age, body mass index, and waist of 52 years, 27kg/m2 and 90cm. 51% were male. Prevalence of A1C≥5.7%, ≥6.0% and ≥6.5% were 54%, 34% and 12%, respectively. Areas under the curve (AUC) for detection of increasing levels dysglycemia or diabetes for RCG were 63%, 66% and 72%, for the ADA DRT the AUCs were 75%, 76% and 81% and for SFS the AUCs were 82%, 84% and 90%, respectively. For each level of dysglycemia or diabetes, the SFS AUC was significantly higher than RCG or the ADA DRT. Conclusions: The noninvasive skin fluorescence spectroscopy measurement outperformed both RCG and the ADA DRT for detection of A1C-defined dysglycemia or diabetes in an at-risk cohort. © 2013 Elsevier Ireland Ltd.


Orchard T.J.,University of Pittsburgh | Lyons T.J.,University of Oklahoma | Cleary P.A.,George Washington University | Braffett B.H.,George Washington University | And 7 more authors.
Diabetes Care | Year: 2013

OBJECTIVE To determine whether skin intrinsic fluorescence (SIF) is associated with longterm complications of type 1 diabetes (T1D) and, if so, whether it is independent of chronic glycemic exposure and previous intensive therapy. RESEARCH DESIGN AND METHODSdWe studied 1,185 (92%) of 1,289 active Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) participants from 2010 to 2011. SIF was determined using a fluorescence spectrometer and related cross-sectionally to recently determined measures of retinopathy (stereo fundus photography), cardiac autonomic neuropathy (CAN; R-R interval), confirmed clinical neuropathy, nephropathy (albumin excretion rate [AER]), and coronary artery calcification (CAC). RESULTSdOverall, moderately strong associations were seen with all complications, before adjustment formean HbA1c over time, which rendered these associations nonsignificant with the exception of sustained AER .30 mg/24 h and CAC, which were largely unaffected by adjustment. However, when examined within the former DCCT treatment group, associations were generally weaker in the intensive group and nonsignificant after adjustment, while in the conventional group, associations remained significant for CAN, sustained AER .30 mg/24 h, and CAC even after mean HbA1c adjustment. CONCLUSIONSdSIF is associated with T1D complications in DCCT\EDIC. Much of this association appears to be related to historical glycemic exposure, particularly in the previously intensively treated participants, inwhomadjustment for HbA1c eliminates statistical significance. © 2013 by the American Diabetes Association.


Conway B.N.,Vanderbilt University | Aroda V.R.,MedStar Research Institute | Maynard J.D.,VeraLight | Matter N.,VeraLight | And 3 more authors.
Diabetes Care | Year: 2011

OBJECTIVE - To determine whether skin intrinsic fluorescence (SIF) was associated with autonomic neuropathy and confirmed distal symmetrical polyneuropathy (CDSP) in 111 individuals with type 1 diabetes (mean age 49 years, mean diabetes duration 40 years). RESEARCH DESIGN AND METHODS - SIF was measured using the SCOUT DM device. Autonomic neuropathy was defined as an electrocardiographic abnormal heart rate response to deep breathing (expiration-to-inspiration ratio <1.1). CDSP was defined using the Diabetes Control and Complications Trial clinical exam protocol (the presence of two or more of the following: symptoms, sensory and/or motor signs, and/or reduced/absent tendon reflexes consistent with DSP) confirmed by the presence of an abnormal age-specific vibratory threshold (using a Vibratron II tester). RESULTS - The prevalence of autonomic neuropathy and CDSP were 61 and 66%, respectively. SIF was higher in those with autonomic neuropathy (P < 0.0001). In multivariable analyses controlling for age and updated mean (18-year average) HbA1c, and allowing for other univariately and clinically significant correlates of autonomic neuropathy, each SD change in SIF was associated with a 2.6-greater likelihood of autonomic neuropathy (P = 0.006). Receiver operating characteristic (ROC) analyses revealed that SIF and updated mean HbA1c accounted for 80 and 57%, respectively, of the area under the curve (AUC) for autonomic neuropathy. SIF also was higher in those with CDSP (P < 0.0001) and remained so in multivariable analyses (odds ratio 2.70; P = 0.005). ROC analyses revealed that SIF and updated mean HbA1c accounted for 78 and 59%, respectively, of the AUC for CDSP. CONCLUSIONS - SIF, a marker of dermal advanced glycation end products, appears to be more strongly associated with the presence of both CDSP and autonomic neuropathy than mean HbA1c. © 2011 by the American Diabetes Association.


Ridder T.D.,TruTouch Technologies | Hull E.L.,VeraLight | Ver Steeg B.J.,TruTouch Technologies | Laaksonen B.D.,TruTouch Technologies
Journal of Biomedical Optics | Year: 2011

Previous works investigated a spectroscopic technique that offered a promising alternative to blood and breath assays for determining in vivo alcohol concentration. Although these prior works measured the dorsal forearm, we report the results of a 26-subject clinical study designed to evaluate the spectroscopic technique at a finger measurement site through comparison to contemporaneous forearm spectroscopic, venous blood, and breath measurements. Through both Monte Carlo simulation and experimental data, it is shown that tissue optical probe design has a substantial impact on the effective path-length of photons through the skin and the signal-to-noise ratio of the spectroscopic measurements. Comparison of the breath, blood, and tissue assays demonstrated significant differences in alcohol concentration that are attributable to both assay accuracy and alcohol pharmacokinetics. Similar to past works, a first order kinetic model is used to estimate the fraction of concentration variance explained by alcohol pharmacokinetics (72.6-86.7%). A significant outcome of this work was significantly improved pharmacokinetic agreement with breath (arterial) alcohol of the finger measurement (meankArt-Fin = 0.111 min- 1) relative to the forearm measurement (mean k Art- For = 0.019 min -1) that is likely due to the increased blood perfusion of the finger. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).


Conway B.,Vanderbilt University | Edmundowicz D.,University of Pittsburgh | Matter N.,VeraLight | Maynard J.,VeraLight | Orchard T.,University of Pittsburgh
Diabetes Technology and Therapeutics | Year: 2010

Background: Coronary artery calcification (CAC) is more severe and occurs at an earlier age in type 1 diabetes. Risk factors for this subclinical marker of atherosclerotic burden, like coronary artery disease (CAD) itself, are not fully identified. One postulated mechanism for the increased CAC observed in type 1 diabetes is the accumulation of advanced glycation end products (AGEs). As certain collagen AGEs fluoresce, skin intrinsic fluorescence (SIF) can act as a novel marker of levels of collagen AGEs. We thus sought to determine the relationship between skin intrinsic fluorescence and CAC in type 1 diabetes. Methods: One hundred five participants in the Pittsburgh Epidemiology of Diabetes Complications study of childhood-onset (age <17 years) type 1 diabetes who had previously undergone electron beam tomography scanning for CAC (80 of whom had follow-up data) had SIF measurements taken using the SCOUT DM® (VeraLight, Inc., Albuquerque, NM). Mean age and diabetes' duration were 49 and 40 years, respectively, at the time of SIF measurement. Results: Seventy-one percent of the study participants had some measurable CAC that was univariately (but not after age adjustment) cross-sectionally associated with SIF (odds ratio=2.51, 1.37-4.59). However, for CAC severity using natural logarithmically transformed scores, SIF was both univariately (P<0.0001) and multivariably (P=0.03) associated with CAC. This relationship was independent of age, a history of CAD, renal function, or renal damage. Receiver operator characteristic analyses revealed that the discriminative ability of SIF to detect CAC went from an area under the curve of 71% for the presence of any CAC to 85% for those with a CAC score >400. Conclusions: The relationship between SIF and CAC appears stronger with more severe calcification. Given the strong relationship of CAC with CAD this finding has important implications and suggests that SIF maybe a useful marker of CAC/CAD risk and potentially a therapeutic target. © Mary Ann Liebert, Inc.


Shah S.,Louisiana State University Health Sciences Center | Baez E.A.,Louisiana State University Health Sciences Center | Felipe D.L.,Louisiana State University Health Sciences Center | Maynard J.D.,VeraLight | And 3 more authors.
Journal of Pediatrics | Year: 2013

Objectives To estimate skin content of advanced glycation endproducts (AGEs) by measurements of skin intrinsic fluorescence (SIF) from youth with diabetes in comparison with a population of youth and adults without diabetes. Study design Using a specialized instrument, skin AGEs were estimated from skin auto-fluorescence induced at 420 nm and corrected for skin pigmentation (SIF420[kx0.5, km0.5]) in children with types 1 and 2 diabetes, as well as children and adults without diabetes. The effect of age, sex, ethnicity, and diabetes status on SIF420[kx0.5, km0.5] was analyzed. Results SIF420[kx0.5, km0.5] increased with chronologic age and was higher in children with diabetes compared with children without diabetes (P =.0001). SIF420[kx0.5, km0.5] from 43% of children with type 1 diabetes and 55% with type 2 diabetes overlapped the range of adults without diabetes. SIF420[kx0.5, km0.5] was higher in girls than boys in patients with diabetes patients. However, there was no effect of sex or race on SIF420 [kx0.5, km0.5] in subjects without diabetes. Conclusions After 4-6 years' exposure to diabetes, many children will have precociously high estimates of skin AGEs, comparable with levels that would naturally accumulate only after ∼25 years of chronologic aging. Potentially, this technology identifies children who are at increased risk for complications. © 2013 Mosby Inc. All rights reserved.


Trademark
VeraLight | Date: 2010-11-09

Medical devices that measure human tissue characteristics for purposes of diagnosing or evaluating patient condition by assessing the response of the tissue to incident electromagnetic radiation, namely, devices that measure glycation end-products; medical devices that screen, predict, diagnose, or assess tissue states relative to blood glucose control; medical devices that indicate the presence, state, or progression of diabetes; and medical devices that measure human tissue characteristics and indicate a corresponding state of health.


Trademark
VeraLight | Date: 2010-03-02

Medical devices that measure human tissue characteristics for purposes of diagnosing or evaluating patient condition by assessing the response of the tissue to incident electromagnetic radiation, namely, devices that measure glycation end-products; medical devices that screen, predict, diagnose, or assess tissue states relative to blood glucose control; medical devices that indicate the presence, state, or progression of diabetes; and medical devices that measure human tissue characteristics and indicate a corresponding state of health.


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