OBJECTIVE:--The clinical value of metabolic syndrome is uncertain. Thus, we examined cardiovascular disease (CVD) and diabetes risk prediction by the National Cholesterol Education Program ...(NCEP)-Adult Treatment Panel III (ATPIII), International Diabetes Federation, and World Health Organization definitions of the metabolic syndrome. RESEARCH DESIGN AND METHODS--We analyzed the risks associated with metabolic syndrome, the NCEP multiple risk factor categories, and 2-h glucose values in the San Antonio Heart Study (n = 2,559; age range 25-64 years; 7.4 years of follow-up). RESULTS:--Both ATPIII metabolic syndrome plus age >=45 years (odds ratio 9.25 95% CI 4.85-17.7) and multiple (two or more) risk factors plus a 10-year coronary heart disease (CHD) risk of 10-20% (11.9 6.00-23.6) had similar CVD risk in men without CHD, as well as CHD risk equivalents. In women counterparts, multiple (two or more) risk factors plus a 10-year CHD risk of 10-20% was infrequent (10 of 1,254). However, either a 10-year CHD risk of 5-20% (7.72 3.42-17.4) or ATPIII metabolic syndrome plus age >=55 years (4.98 2.08-12.0) predicted CVD. ATPIII metabolic syndrome increased the area under the receiver operating characteristic curve of a model containing age, sex, ethnic origin, family history of diabetes, and 2-h and fasting glucose values (0.857 vs. 0.842, P = 0.013). All three metabolic syndrome definitions imparted similar CVD and diabetes risks. CONCLUSIONS:--Metabolic syndrome is associated with a significant CVD risk, particularly in men aged >=45 years and women aged >=55 years. The metabolic syndrome predicts diabetes beyond glucose intolerance alone.
Whether apolipoprotein B (apoB) or non-high-density lipoprotein cholesterol (HDL-C) adds to the predictive power of low-density lipoprotein cholesterol (LDL-C) for cardiovascular risk remains ...controversial.
This meta-analysis is based on all the published epidemiological studies that contained estimates of the relative risks of non-HDL-C and apoB of fatal or nonfatal ischemic cardiovascular events. Twelve independent reports, including 233 455 subjects and 22 950 events, were analyzed. All published risk estimates were converted to standardized relative risk ratios (RRRs) and analyzed by quantitative meta-analysis using a random-effects model. Whether analyzed individually or in head-to-head comparisons, apoB was the most potent marker of cardiovascular risk (RRR, 1.43; 95% CI, 1.35 to 1.51), LDL-C was the least (RRR, 1.25; 95% CI, 1.18 to 1.33), and non-HDL-C was intermediate (RRR, 1.34; 95% CI, 1.24 to 1.44). The overall comparisons of the within-study differences showed that apoB RRR was 5.7%>non-HDL-C (P<0.001) and 12.0%>LDL-C (P<0.0001) and that non-HDL-C RRR was 5.0%>LDL-C (P=0.017). Only HDL-C accounted for any substantial portion of the variance of the results among the studies. We calculated the number of clinical events prevented by a high-risk treatment regimen of all those >70th percentile of the US adult population using each of the 3 markers. Over a 10-year period, a non-HDL-C strategy would prevent 300 000 more events than an LDL-C strategy, whereas an apoB strategy would prevent 500 000 more events than a non-HDL-C strategy.
These results further validate the value of apoB in clinical care.
River to floodplain hydrologic connectivity is strongly enhanced by beaver- (Castor canadensis) engineered channel water diversions. The hydroecological impacts are wide ranging and generally ...positive, however, the hydrogeochemical characteristics of beaver-induced flowpaths have not been thoroughly examined. Using a suite of complementary ground- and drone-based heat tracing and remote sensing methodology we characterized the physical template of beaver-induced floodplain exchange for two alluvial mountain streams near Crested Butte, Colorado, USA. A flowpath-oriented perspective to water quality sampling allowed characterization of the chemical evolution of channel water diverted through floodplain beaver ponds and ultimately back to the channel in ‘beaver pond return flows’. Subsurface return flow seepages were universally suboxic, while ponds and surface return flows showed a range of oxygen concentration due to in-situ photosynthesis and atmospheric mixing. Median concentrations of reduced metals: manganese (Mn), iron (Fe), aluminum (Al), and arsenic (As) were substantially higher along beaver-induced flowpaths than in geologically controlled seepages and upstream main channel locations. The areal footprint of reduced return seepage flowpaths were imaged with surface electromagnetic methods, indicating extensive zones of high-conductivity shallow groundwater flowing back toward the main channels and emerging at relatively warm bank seepage zones observed with infrared. Multiple-depth redox dynamics within one focused seepage zone showed coupled variation over time, likely driven by observed changes in seepage rate that may be controlled by pond stage. High-resolution times series of dissolved Mn and Fe collected downstream of the beaver-impacted reaches demonstrated seasonal dynamics in mixed river metal concentrations. Al time series concentrations showed proportional change to Fe at the smaller stream location, indicating chemically reduced flowpaths were sourcing Al to the channel. Overall our results indicated beaver-induced floodplain exchanges create important, and perhaps dominant, transport pathways for floodplain metals by expanding chemically-reduced zones paired with strong advective exchange.
Display omitted
•Beavers enhance multi-season alluvial floodplain hydrologic connectivity.•Enhanced floodplain water storage creates reducing conditions and mobilizing metals.•Beaver pond return flows source natural metals to the main channel.•Beaver-induced floodplain exchange alters river chemistry in small and large streams.•Mobility of metals and contaminants likely impacts beaver-enabled stream restoration.
We have examined the relationship between artificially sweetened beverage (ASB) consumption and long‐term weight gain in the San Antonio Heart Study. From 1979 to 1988, height, weight, and ASB ...consumption were measured among 5,158 adult residents of San Antonio, Texas. Seven to eight years later, 3,682 participants (74% of survivors) were re‐examined. Outcome measures were incidence of overweight/obesity (OW/OBinc) and obesity (OBinc) (BMI ≥ 25 and ≥ 30 kg/m2, respectively), and BMI change by follow‐up (ΔBMI, kg/m2). A significant positive dose‐response relationship emerged between baseline ASB consumption and all outcome measures, adjusted for baseline BMI and demographic/behavioral characteristics. Consuming >21 ASBs/week (vs. none) was associated with almost‐doubled risk of OW/OB (odds ratio (OR) = 1.93, P = 0.007) among 1,250 baseline normal‐weight (NW) individuals, and doubled risk of obesity (OR = 2.03, P = 0.0005) among 2,571 individuals with baseline BMIs <30 kg/m2. Compared with nonusers (+1.01 kg/m2), ΔBMIs were significantly higher for ASB quartiles 2–4: +1.46 (P = 0.003), +1.50 (P = 0.002), and +1.78 kg/m2 (P < 0.0001), respectively. Overall, adjusted ΔBMIs were 47% greater among artificial sweetner (AS) users than nonusers (+1.48 kg/m2 vs. +1.01 kg/m2, respectively, P < 0.0001). In separate analyses—stratified by gender; ethnicity; baseline weight category, dieting, or diabetes status; or exercise‐change category—ΔBMIs were consistently greater among AS users. These differences, though not significant among exercise increasers, or those with baseline diabetes or BMI >30 kg/m2 (P = 0.069), were significant in all 13 remaining strata. These findings raise the question whether AS use might be fueling—rather than fighting—our escalating obesity epidemic.
What Is the Best Predictor of Future Type 2 Diabetes?
Muhammad A. Abdul-Ghani , MD, PHD ,
Ken Williams , MS ,
Ralph A. DeFronzo , MD and
Michael Stern , MD
From the Divisions of Diabetes and Clinical ...Epidemiology, University of Texas Health Science Center at San Antonio, San Antonio,
Texas
Address correspondence and reprint requests to Muhammad A. Abdul-Ghani, MD, PhD, Diabetes Division, University of Texas Health
Science Center, 7703 Floyd Curl Dr., MS 7886, San Antonio, TX 78229. E-mail: albarado{at}uthscsa.edu
Abstract
OBJECTIVE —We sought to assess insulin secretion/insulin resistance index in predicting the risk for future type 2 diabetes
RESEARCH DESIGN AND METHODS —A total of 1,551 nondiabetic subjects from the San Antonio Heart Study received an oral glucose tolerance test (OGTT) with
measurement of plasma glucose and insulin concentrations at 0, 30, 60, and 120 min at baseline and after 7–8 years of follow-up.
Insulin secretion/insulin resistance index was calculated as the product of Matsuda index and ΔI 0–30 /ΔG 0–30 or ΔI 0–120 /ΔG 0–120 . The discriminatory power of various prediction models for development of type 2 diabetes was tested with the area under
the receiver-operating characteristic (ROC) curve.
RESULTS —Insulin secretion/insulin resistance index (0- to 30- and 0- to 120-min time periods) had the greatest areas under the ROC
curve (0.85 and 0.86, respectively), which were significantly greater than the 2-h plasma glucose concentration during the
OGTT or the San Antonio Diabetes Prediction Model (SADPM) ( P < 0.001 and P < 0.0001, respectively). A model based on the combination of the SADPM and a modified version of the insulin secretion/insulin
resistance index or 1-h plasma glucose concentration had equal power to predict the risk for future type 2 diabetes compared
with the insulin secretion/insulin resistance index.
CONCLUSIONS —The insulin secretion/insulin resistance index is useful as a predictor of future development of type 2 diabetes. A model
based on the combination of the SADPM and either a modified version of the insulin secretion/insulin resistance index or 1-h
plasma glucose concentration can equally predict future type 2 diabetes.
IGT, impaired glucose tolerance
NGT, normal glucose tolerance
OGTT, oral glucose tolerance test
ROC, receiver-operating characteristic
SADPM, San Antonio Diabetes Prediction Model
Footnotes
Published ahead of print at http://care.diabetesjournals.org on 23 March 2007. DOI: 10.2337/dc06-1331.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore
be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Accepted March 9, 2007.
Received June 26, 2006.
DIABETES CARE
Does the Metabolic Syndrome Improve Identification of Individuals at Risk of Type 2 Diabetes and/or Cardiovascular Disease?
Michael P. Stern , MD 1 ,
Ken Williams , MS 1 ,
Clicerio ...González-Villalpando , MD 2 ,
Kelly J. Hunt , PHD 1 and
Steven M. Haffner , MD 1
1 Division of Clinical Epidemiology, Department of Medicine, University of Texas Health Science Center, San Antonio, Texas
2 Centro de Estudios en Diabetes, The American British Cowdray Hospital and Unidades de Investigación Médica en Enfermedades
Metabólicas y Epidemiología Clínica, Hospital Gabriel Mancera, Instituto Mexicano del Seguro Social, Mexico City, Mexico
Address correspondence and reprint requests to Michael P. Stern, MD, Division of Clinical Epidemiology, Department of Medicine,
University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229-3900. E-mail: stern{at}uthscsa.edu
Abstract
OBJECTIVE —The metabolic syndrome has been promoted as a method for identifying high-risk individuals for type 2 diabetes and cardiovascular
disease (CVD). We therefore sought to compare this syndrome, as defined by the National Cholesterol Education Program, to
the Diabetes Predicting Model and the Framingham Risk Score as predictors of type 2 diabetes and CVD, respectively.
RESEARCH DESIGN AND METHODS —A population-based sample of 1,709 initially nondiabetic San Antonio Heart Study (SAHS) participants were followed for 7.5
years, 195 of whom developed type 2 diabetes. Over the same time interval, 156 of 2,570 SAHS participants experienced a cardiovascular
event. A population-based sample of 1,353 initially nondiabetic Mexico City Diabetes Study (MCDS) participants were followed
for 6.5 years, 125 of whom developed type 2 diabetes. Baseline measurements included medical history, age, sex, ethnicity,
smoking status, BMI, blood pressure, fasting and 2-h plasma glucose levels, and fasting serum total and HDL cholesterol and
triglycerides.
RESULTS —The sensitivities for predicting diabetes with the metabolic syndrome were 66.2 and 62.4% in the SAHS and the MCDS, respectively,
and the false-positive rates were 27.8 and 38.7%, respectively. The sensitivity and false-positive rates for predicting CVD
with the metabolic syndrome in the SAHS were 67.3 and 34.2%, respectively. At corresponding false-positive rates, the two
predicting models had significantly higher sensitivities and, at corresponding sensitivities, significantly lower false-positive
rates than the metabolic syndrome for both end points. Combining the metabolic syndrome with either predicting model did not
improve the prediction of either end point.
CONCLUSIONS —The metabolic syndrome is inferior to established predicting models for either type 2 diabetes or CVD.
aROC, area under the received operating characteristic curve
CVD, cardiovascular disease
IGT, impaired glucose tolerance
MCDS, Mexico City Diabetes Study
NCEP ATP-III, National Cholesterol Education Program Adult Treatment Panel III
ROC, receiver operating characteristic
SAHS, San Antonio Heart Study
WHO, World Health Organization
Footnotes
Additional information for this article can be found in an online appendix at http://care.diabetesjournals.org .
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
See accompanying editorial, p. 2761.
Accepted June 28, 2004.
Received April 29, 2004.
DIABETES CARE
Summary
Background
Follicular Unit Extraction (FUE) is considered to be a minimally invasive procedure, and the injury to the donor area caused by a sharp punch may result in dermal fibrosis and ...clinically observed hypopigmentation.
Objective
To evaluate with advanced image processing the efficacy of using 0.9% normal saline in minimizing the injury to the donor area in FUE donor harvesting.
Patients and methods
The term acute extraction (AE) is used to describe the donor harvesting technique, whereby a follicular unit (FU) is removed with a punch that is aligned parallel with the exit angle of the hair follicle. The term vertical extraction (VE) describes the technique where a FU is removed in like manner, but normal saline is injected intradermally prior to harvesting so the punch being perpendicular to the skin. Thirty‐five patients were selected for this study to apply both harvesting techniques and then to compare the differences in wound surface size and skin mass removed by the punch.
Results
A significant reduction in the mean values of wound surface and skin mass was recorded in vertical extraction compared to those in acute extraction.
Conclusion
The injection of normal saline prior to harvesting proved to be very efficient in minimizing skin injury in FUE harvesting.
To assess the utility of clinical definitions of the metabolic syndrome (MetS) to identify individuals with increased cardiovascular risk, we examined the relation between the MetS, using both the ...National Cholesterol Education Program (NCEP) and the World Health Organization definitions, and all-cause and cardiovascular mortality in San Antonio Heart Study participants enrolled between 1984 and 1988.
Among 2815 participants, 25 to 64 years of age at enrollment, 509 met both criteria, 197 met NCEP criteria only, and 199 met WHO criteria only. Over an average of 12.7 years, 229 deaths occurred (117 from cardiovascular disease). Moreover, in the primary prevention population of 2372 participants (ie, those without diabetes or cardiovascular disease at baseline), 132 deaths occurred (50 from cardiovascular disease). In the primary prevention population, the only significant association adjusted for age, gender, and ethnic group was between NCEP-MetS and cardiovascular mortality (hazard ratio HR, 2.01; 95% CI, 1.13-3.57). In the general population, all-cause mortality HRs were 1.47 (95% CI, 1.13-1.92) for NCEP-MetS and 1.27 (95% CI, 0.97-1.66) for WHO-MetS. Furthermore, for cardiovascular mortality, there was evidence that gender modified the predictive ability of the MetS. For women and men, respectively, HRs for NCEP-MetS were 4.65 (95% CI, 2.35-9.21) and 1.82 (95% CI, 1.14-2.91), whereas HRs for WHO-MetS were 2.83 (95% CI, 1.55-5.17) and 1.15 (95% CI, 0.72-1.86).
In summary, although both definitions were predictive in the general population, the simpler NCEP definition tended to be more predictive in lower-risk subjects.
OBJECTIVE—High lipoprotein(a) (Lpa) is the most common genetic dyslipidemia and is a causal factor for myocardial infarction (MI) and aortic stenosis (AS). We sought to estimate the population impact ...of Lp(a) lowering that could be achieved in primary prevention using the therapies in development.
APPROACH AND RESULTS—We used published data from 2 prospective cohorts. High Lp(a) was defined as ≥50 mg/dL (≈20th percentile). Relative risk, attributable risk, the attributable risk percentage, population attributable risk, and the population attributable risk percentage were calculated as measures of the population impact. For MI, the event rate was 4.0% versus 2.8% for high versus low Lp(a) (relative risk, 1.46; 95% confidence interval CI, 1.45–1.46). The attributable risk was 1.26% (95% CI, 1.24–1.27), corresponding to 31.3% (95% CI, 31.0–31.7) of the excess MI risk in those with high Lp(a). The population attributable risk was 0.21%, representing a population attributable risk percentage of 7.13%. For AS, the event rate was 1.51% versus 0.78% for high versus low Lp(a) (relative risk, 1.95; 95% CI, 1.94–1.97). The attributable risk was 0.74% (95% CI, 0.73–0.75), corresponding to 48.8% (95% CI, 48.3–49.3) of the excess AS risk in those with high Lp(a). The population attributable risk was 0.13%, representing a population attributable risk percentage of 13.9%. In sensitivity analyses targeting the top 10% of Lp(a), the population attributable risk percentage was 5.2% for MI and 7.8% for AS.
CONCLUSIONS—Lp(a) lowering among the top 20% of the population distribution for Lp(a) could prevent 1 in 14 cases of MI and 1 in 7 cases of AS, suggesting a major impact on reducing the burden of cardiovascular disease. Targeting the top 10% could prevent 1 in 20 MI cases and 1 in 12 AS cases.
PDF
