Sonia Kapur, Ph.D., Margaret N. Groves, M.Phil., David T. Zava, Ph.D., and Sanjay Kapur, Ph.D.

Transcription

1 Journl of Dibetes Science nd Technology Volume 4, Issue 2, Mrch 2010 Dibetes Technology Society SYMPOSIUM Postprndil Insulin nd Triglycerides fter Different Brekfst Mel Chllenges: Use of Finger Stick Cpillry Dried Blood Spots to Study Postprndil Dysmetbolism Soni, Ph.D., Mrgret N. Groves, M.Phil., Dvid T. Zv, Ph.D., nd Snjy, Ph.D. Abstrct Bckground: High levels of insulin nd lipids following mel re recognized risk fctors for therosclerosis. Monitoring such risk fctors in the generl popultion is hmpered by the inconvenience of venipuncture blood collection, prticulrly for both premel nd postmel nlyses. This study exmined insulin nd triglyceride levels in dried blood spots (DBSs) collected fter different brekfst mel chllenges to ssess the potentil of this method for risk ssessment. Methods: Glucose levels were mesured using glucose meter, nd insulin nd triglycerides were determined in DBS smples collected from 19 helthy volunteers before nd t four time points up to 2.5 h fter consuming ech of five typicl brekfst mels vrying in nutritionl composition. Results: At 2 h, glucose ws within norml postprndil vlues (<140 mg/dl) for ll mels; significntly lower glucose ws seen fter mel 2 (the lowest crbohydrte content) compred to the other mels. Insulin returned to norml fsting levels (<15 µiu/ml) in significntly more subjects (90%) fter mel 2 nd significntly fewer subjects (31%) fter mel 4 (highest crbohydrte content) thn the other mels. Triglycerides were elevted to similr extent in ll subjects, with no significnt differences between mels; levels were still rising t 2.5 h. Conclusions: Subjects were ble to collect blood spots with minimum disruption to their norml dily ctivities. Reltive ese of collection, nlyte stbility in dried blood, nd the close correltion with serum levels tht we hve previously demonstrted mkes DBS convenient nd simple tool for ssessing the individul impct of different diets on postprndil dysmetbolism. J Dibetes Sci Technol 2010;4(2): Author Affilition: ZRT Lbortory, LLC, Beverton, Oregon Abbrevitions: (BMI) body mss index, (CHD) coronry hert disese, (DBS) dried blood spot, (PPG) postprndil glucose Keywords: blood spot, crdiometbolic risk, insulin, postprndil, postprndil dysmetbolism, triglycerides Corresponding Author: Snjy, Ph.D., ZRT Lbortory, LLC, 8605 SW Creekside Plce, Beverton, OR 97008; emil ddress skpur@zrtlb.com 236

2 Introduction The metbolic conditions tht predispose individuls to the development of therosclerosis nd coronry hert disese (CHD) my be lrgely postprndil phenomenon described s postprndil dysmetbolism. 1 O Keefe nd collegues 2 hve reviewed dietry strtegies tht lower risk of crdiovsculr disese by reducing postprndil glucose (PPG), lipids, nd inflmmtion. In societies such s the United Sttes tht predominntly hve positive energy blnce, such tht cloric intke exceeds clorie expenditure, obesity is prevlent, nd the incidence of metbolic syndrome, dibetes, nd crdiovsculr disese is rising. Poor dietry hbits result in much of n individul s time being spent in nonfsting stte. 3 Viscerl obesity hs been shown to increse levels of therogenic lipid prticles fter mel chllenge. 4 There is incresing evidence tht postprndil levels of insulin nd triglycerides re vluble clinicl tool for determining risk for developing crdiovsculr disese nd dibetes. In people with dibetes, postprndil insulin levels re higher thn in people without dibetes. However, when monitored over time, declining postprndil insulin levels in ptients with type 2 dibetes re powerful indictor of deteriorting blood sugr control, becuse they re mesure of the decline in bet-cell responsiveness s the disese progresses. 5,6 In subjects with no known dibetes, high postprndil insulin levels hve been found to be n independent risk fctor for CHD. 7,8 Triglyceride levels mesured 2 4 h fter mel re lso highly predictive of crdiovsculr events, especilly in women. 9,10 Crdiometbolic risk mrkers re routinely mesured in fsting blood smples in order to provide meningful levels of cholesterol, insulin, nd triglycerides tht re not ffected by recent food consumption. However, stndrdized protocols hve not yet been estblished for the ssessment of nonfsting triglycerides nd insulin. 3 Clinicl studies reporting postprndil prmeters hve used either vriety of types of mel or n orl glucose or ft lod tht does not represent wht might be consumed by n individul in their choice of typicl mel. It hs therefore been difficult to determine pproprite reference rnges for postprndil levels of these mrkers nd cutoffs tht my define incresed risk. Another importnt fctor is the inconvenience of collecting blood smples t vrious time points fter eting, s this requires stying t blood collection center or repetedly returning to hve blood collected. The mjority of clinicl mel studies involve intrvenous ctheteriztion for collection of multiple smples fter mel chllenge. These studies typiclly cn only ssess subject fter single mel nd require the subject to remin in the clinic for severl hours during smple collection. This rtificil clinicl environment nd type of mel served re not wht would be hppening during tht subject s norml dy, prticulrly with respect to physicl ctivity or the types of foods they routinely consume. Cpillry (finger stick) blood spot collection on filter pper by n individul in the home or work environment, on the other hnd, ffords simple nd convenient wy to collect blood smples. Such methods of blood collection cn be employed in lrger-scle epidemiologicl studies looking t postprndil dysmetbolism nd its longerterm effects on crdiovsculr disese nd dibetes in people in their norml living sitution fter eting typicl mels. To pprecite the simplicity nd convenience of using dried blood spots (DBSs) to study dysmetbolism, we investigted postprndil levels of insulin nd triglycerides in DBSs up to 2.5 h fter five different brekfst mels in 19 helthy volunteers. The im ws to determine whether different mels would elicit differing responses nd to identify suitble protocol for detecting postprndil dysmetbolism for routine crdiometbolic risk ssessment. Methods The procedures followed were in ccordnce with the current revision of the Helsinki Declrtion, nd ll subjects gve their informed consent. Nineteen helthy volunteers, 13 women nd 6 men, were recruited from ZRT Lbortory stff fter being informed of the contents of ll five mels nd confirming tht they would be ble to et ll of them. None of the volunteers ws receiving sttin medictions. Volunteers were sked to fst by consuming nothing except wter from the previous evening until rriving for the study. Length of fsting time ws recorded on 237

3 rrivl; fsting time vried between 10 nd 14 h over the course of the study. On ech test dy, volunteers provided fsting blood spot smple nd then te one of five test mels (see Tble 1 for mel composition). Blood spot smples were then collected 30 min, 1 h, 2 h, nd 2.5 h fter finishing the mel during the volunteers norml workdy ctivities. At lest one week elpsed between ech test mel. Following finger stick with Unistik lncets (Fisher Scientific), blood drops were collected on filter pper blood spot collection crds (Whtmn 901). Immeditely prior to collecting blood spots, the first drop of blood ws used to test for glucose using glucose meter (One Touch Ultr Mini), nd the subsequent drops were pplied to the filter pper. Blood spots on the collection crds were llowed to dry t room temperture for one dy, nd the smples were then stored individully in Ziploc bgs with desiccnt t -70 ºC until ssys were run. Insulin nd triglyceride levels were mesured in extrcted DBS s previously described, 11 where correltion with simultneously collected venous serum smples for both nlytes ws demonstrted (r = 0.93 nd 0.91, respectively). All ssys were run on the sme dy fter dministrtion of ll test mels nd within mximum of six weeks fter smple collection. Qulity control smples were included with ech ssy. Intr- nd interssy coefficients of vrition of the ssy re <10% for triglycerides nd <15% for insulin over the rnge of vlues mesured in this study. All volunteers were ssessed for body mss index (BMI) nd criteri for metbolic syndrome. 12 Five of the 19 volunteers met the Ntionl Cholesterol Eduction Pnel s criteri for metbolic syndrome (three or more of the following: wist circumference >40 in. in men or 35 in. in women, fsting triglycerides >150 mg/dl, high-density lipoprotein cholesterol <40 mg/dl for men or <50 mg/dl for women, blood pressure >130/85, nd fsting plsm glucose >110 mg/dl). Clinicl dibetes ws n exclusion criterion when enrolling volunteers s study subjects. However, during the course of the study, fsting blood glucose levels in four subjects were observed to be just within the rnge currently defined by the Americn Dibetes Assocition s predibetic, i.e., between 100 nd 125 mg/dl; fsting blood glucose levels, verged over the study test dys for ech of these four subjects, were 100, 104, 104, nd 105 mg/dl. For purposes of sttisticl nlysis, both insulin nd triglyceride levels were trnsformed into norml/bnorml nd optiml/nonoptiml clssifictions. Insulin levels were clssified s norml if they were 15 µiu/ml. Levels 8 µiu/ml were considered optiml. Triglyceride levels were considered norml if they were 150 mg/dl nd were considered optiml if they were 100 mg/dl. All glucose levels were in the norml 2 h postprndil rnge (<140 mg/dl) nd thus could not be trnsformed into dichotomous vrible. A mixed model logistic regression ws used to nlyze the dichotomous insulin nd triglyceride dt. Tble 1. Test Mel Descriptions nd Nutritionl Composition Mel # Mel contents Nutritionl composition Clories (kcl) 1 2 glzed donuts (Krispy Kreme, totl 104 g), 1 fruit smoothie (Dnnon, 207 ml) Crbohydrte: 79 g (sugrs 53 g) = 69% (46%) Ft: 26.5 g = 23% Protein: 9 g = 8% Fiber: 2 g boiled eggs, 2 susges (totl 35 g), 250 ml 2% milk Crbohydrte: 13.3 g (sugrs 11 g) = 23% (19%) Ft: 25.6 g = 45% Protein: 18.6 g = 32% Fiber: 0 g bgel (120 g) with 1 28 g pcket crem cheese, 1 hrd-boiled egg, 250 ml 2% milk Crbohydrte: 61.4 g (sugrs 16.3 g) = 63% (17%) Ft: 13.8 g = 14% Protein: 23 g = 23% Fiber: 2 g pnckes (116 g) with 30 ml syrup, te with 9 ml crem (hlf nd hlf), g sugr pcket Crbohydrte: 78 g (sugrs 35 g) = 83% (37%) Ft: 10 g = 11% Protein: 6 g = 6% Fiber: 1 g pcket (50 g) instnt otmel, 28 g lmonds, 1 medium Grnny Smith pple (150 g), 125 ml skim milk Crbohydrte: 67 g (sugrs 30.5 g) = 67% (31%) Ft: 16.5 g = 17% Protein: 16.4 g = 16% Fiber: 11 g

4 Results Glucose, insulin, nd triglyceride levels verged over ll mels for ll volunteers t ech time point re shown in Figure 1. Glucose nd insulin peked t the 30 min postprndil time point nd then declined. Triglycerides showed more grdul increse nd tended to be still rising t the 2.5 h time point. Becuse of overll higher triglyceride levels in the subjects who met the criteri for metbolic syndrome, the triglycerides grph shows metbolic syndrome nd nonmetbolic syndrome subjects seprtely. For nlyses of between-mel differences, the 2 h time point ws chosen becuse published studies looking t postprndil hyperinsulinemi 5,7,8,13 hve used this time point, t which glucose nd insulin levels re expected to hve returned to norml vlues in helthy subjects. Plsm glucose concentrtions normlly pek within 1 h fter mel nd return to norml vlues within 2 3 h. 14 Popultion studies of postprndil hypertriglyceridemi hve found it to be most predictive of crdiovsculr events when mesured 2 to 4 h fter eting. 10 Figures 2 4 show men glucose, insulin, nd triglyceride levels for ll subjects t bseline nd t the 2 h time point for mels 1 5. For sttisticl nlysis of the between-mel differences in postprndil insulin levels, mixed logistic regression model for insulin ws tested for both the norml/bnorml clssifiction nd the optiml/nonoptiml clssifiction. The model ws identicl for both outcome mesures. Prticipnts gender nd BMI were included in the model to control for their influence, s ws ech prticipnt s bseline (preprndil) insulin (clssified s norml/bnorml or optiml/nonoptiml using the sme criteri s those described erlier) for ech mel. Gender, bseline insulin, nd mel type were ll treted s ctegoricl vribles, nd prticipnts were treted s repeted vrible. The model for norml insulin resulted in good fit. Neither BMI (p >.28) nor bseline norml insulin were sttisticlly significnt (p >.32), but gender nd mels both displyed trends towrd significnce (gender p <.08; mel p <.08). The model for optiml insulin lso resulted in good fit. Gender ws not significnt (p >.36), but bseline optiml insulin tended towrd significnce (p <.11). Both mels (p <.03) nd BMI (p <.02) were significnt. Figure 1. Glucose, insulin, nd triglyceride levels (including ll subjects, men vlue ± stndrd devition) for ll mels t ech time point. Subjects with metbolic syndrome re shown seprtely from subjects without metbolic syndrome for triglycerides, becuse triglyceride levels were substntilly higher overll in metbolic syndrome subjects. Glucose nd insulin levels both peked t the 30 min time point, while triglycerides showed grdul increse continuing through the 2.5 h time point. At 2 h, glucose ws comprble to bseline levels. MS, metbolic syndrome; N, subjects without metbolic syndrome. A Wilcoxon pired sign test ws then used to compre prticipnts norml/bnorml nd optiml/nonoptiml insulin clssifictions for ny given mel to every other mel (using only prticipnts who hd dt for both mels in given piring), for totl of 10 comprisons. Tble 2 displys the proportion of prticipnts who hd norml insulin levels for given mel, nd the tble note indictes which mel comprisons were significnt. Mel 2 produced the highest proportion of norml 239

5 insulin clssifictions, nd mel 4 produced the lowest proportion of norml insulin clssifictions. Tble 3 provides the sme informtion using the optiml/nonoptiml clssifiction. Agin, mel 2 produced the highest proportion of optiml insulin clssifictions, nd mel 4 produced the lowest proportion of optiml mel clssifictions. Mixed logistic regression models identicl to those for insulin were used to exmine norml/bnorml nd optiml/ nonoptiml triglyceride clssifictions, substituting the pproprite bseline triglyceride clssifiction into the models. For the norml clssifiction, the model ws resonble fit. Neither gender (p >.53) nor mels (p >.43) nor BMI (p >.25) were significnt. Bseline norml/ bnorml triglycerides were significnt predictor (p <.04). For the optiml clssifiction, the model ws very good fit. Gender ws not significnt (p >.59). Both bseline optiml/nonoptiml triglycerides (p <.04) nd BMI (p <.05) were significnt, nd mels tended towrd significnce (p <.09). Tble 2. Number nd Percentge of Subjects with Norml Insulin ( 15 µiu/ml) for Ech Mel t 2 h Postprndil Mel number Figure 2. Men ± stndrd devition glucose levels t bseline nd t 2 h postprndil for mels 1 to 5. Norml/totl n 13/16 17/19 12/18 5/16 10/14 % norml 81% 90% 67% 31% 71% Anlysis of between-mel comprisons showed tht mel 4 hd lower percentge of people with norml levels nd mel 2 produced tendency for hving higher percentge of people with norml levels. Significntly different mel/mel comprisons were 1 to 4 (Z = 2.45, p <.014, 14 persons), 2 to 4 (Z = 3.00, p <.003, 16 persons), 3 to 4 (Z = 2.00, p <.046, 15 persons), 5 to 4 (Z = 2.00, p <.046, 13 persons), nd 3 to 2 (Z = 2.24, p <.025, 18 persons). Number of persons indictes the number of subjects for whom dt were vilble nd who te both mels in the given piring; subjects who did not et both mels were excluded from the nlysis for tht piring. All other mel/mel comprisons were nonsignificnt. Figure 3. Men ± stndrd devition DBS insulin levels t bseline nd t 2 h postprndil for mels 1 to 5. Tble 3. Number nd Percentge of Subjects with Optiml Insulin Levels ( 8 µiu/ml) for Ech Mel t 2 h Postprndil Mel number Optiml/totl (n) 3/16 12/19 7/18 3/16 7/14 % optiml 19% 63% 39% 19% 50% Figure 4. Men ± stndrd devition DBS triglyceride levels t bseline nd t 2 h postprndil for mels 1 to 5. Anlysis of between-mel comprisons showed tht mel 4 hd lower percentge of people with optiml levels nd mel 2 hd higher percentge of people with optiml levels. Significntly different (p <.10) mel/mel comprisons were 2 to 4 (Z = 2.65, p <.008, 16 persons), 3 to 4 (Z = 1.73, p <.083, 15 persons), 5 to 4 (Z = 1.73, p <.083, 13 persons), 1 to 2 (Z = 3.00, p <.003, 16 persons), 3 to 2 (Z = 1.67, p <.096, 18 persons), 5 to 2 (Z = 1.73, p <.083, 14 persons), nd 1 to 5 (Z = 2.00, p <.046, 12 persons). Number of persons indictes the number of subjects for whom dt were vilble nd who te both mels in the given piring; subjects who did not et both mels were excluded from the nlysis for tht piring. All other mel/mel comprisons were nonsignificnt. 240

6 As for insulin, Wilcoxon pired sign tests were used to compre triglycerides for ll mels to one nother. Proportions of norml nd optiml triglyceride levels re presented in Tbles 4 nd 5. Unlike insulin, no melto-mel comprisons of triglycerides were sttisticlly significnt. It should be noted tht t 2 h postprndil, fr fewer triglyceride levels were norml or optiml thn ws the cse for insulin t 2 h. The mixed liner regression model for glucose resulted in good fit. Neither BMI (p >.71), bseline glucose (p >.77), nor gender were sttisticlly significnt (p >.72), but mel type ws significnt (p <.008). A Wilcoxon pired sign test ws then used to compre prticipnts glucose levels for ny given mel to every other mel (using only prticipnts who hd dt for both mels in given piring), for totl of 10 comprisons. Becuse of the dy-to-dy vribility in bseline glucose levels within individuls, ccommodtion ws done by subtrcting bseline glucose levels from glucose 2 h levels nd using tht difference score s the unit of nlysis. Tble 6 displys the prticipnts mens nd stndrd devitions for the chnge in glucose from bseline to 2 h for ech mel nd the results of the mel-to-mel comprisons. Mel 2 produced slight decrese in glucose levels overll t 2 h reltive to bseline nd differed significntly from the other four mels. Mels 1, 3, 4, nd 5 did not differ significntly from one nother. Tble 4. Number nd Percentge of Subjects with Norml Triglycerides ( 150 mg/dl) by Mel t 2 h Postprndil Mel number Norml/totl (n) 8/16 10/19 8/18 8/16 9/14 % norml 50% 53% 44% 50% 64% None of the mel/mel comprisons ws sttisticlly significnt. Tble 5. Number nd Percentge of Subjects with Optiml Triglycerides ( 100 mg/dl) by Mel t 2 h Postprndil Mel number Optiml/totl (n) 4/16 5/19 6/18 5/16 6/14 % optiml 25% 26% 33% 31% 43% None of the mel/mel comprisons ws sttisticlly significnt. When subjects with (5 subjects) or without (14 subjects) metbolic syndrome were nlyzed seprtely, similr between-mel differences were seen for insulin, nd for triglycerides, the min difference between the two groups ws generlly higher levels throughout in subjects with metbolic syndrome. However, becuse of the smll number of subjects, there ws limited sttisticl power in drwing ny seprte conclusions for this group. Discussion As the body of evidence for the impct of diet nd lifestyle on long-term risk of crdiovsculr disese nd dibetes grows, efficient wys of studying risk mrkers tht cn help to provide strtegies for mnging these helth problems re urgently needed. With the identifiction of postprndil dysmetbolism s n importnt risk fctor, it is becoming pprent tht trditionl fsting blood drws my no longer be pproprite for totl risk ssessment. Collection of postprndil smples requires tht subjects hve eten mel within specific time of smple collection, nd studies investigting the phenomenon my require multiple smples t rnge of postprndil times. The inherent complictions in ttending clinics for blood drw men tht such studies could not be crried out under the conditions of norml dy. Tble 6. Chnge in Glucose between Bseline nd 2 h: Differences between Mels Mel number Number of subjects Bseline to 2 h difference score for glucose Men Stndrd devition Minimum Mximum Anlysis of between-mel comprisons showed tht mel 2 produced the only significnt chnge in glucose t 2 h reltive to bseline nd resulted in lower men glucose t 2 h compred to bseline. Significntly different (p <.10) mel/mel comprisons were 2 to 1 (Z = 2.80, p <.005, 19 persons), 2 to 3 (Z = 2.72, p <.007, 19 persons), 2 to 4 (Z = 2.84, p <.005, 17 persons), 2 to 5 (Z = 2.62, p <.024, 15 persons), nd 4 to 5 (Z = 1.85, p <.064, 15 persons). Number of persons indictes the number of subjects for whom dt were vilble nd who te both mels in the given piring; subjects who did not et both mels were excluded from the nlysis for tht piring. The five remining mel/mel comprisons were ll nonsignificnt, with p >

7 However, blood spot collection llows convenient, simple smple collection t home or t work while subjects continue their dily ctivities. This opens up the significnt possibility of studying postprndil dysmetbolism, either under prescribed dietry conditions or s mens of studying people who re llowed to consume their regulr diets, so tht long-term risks cn be ssessed. Postprndil glucose mesurement hs long been used s determinnt of glycemic control in the medicl mngement of dibetes; it is esily monitored using glucose meter nd requires no blood drw. Postprndil glucose provides resonble ssessment of postprndil hyperglycemi; however, there is limited clinicl vlue in monitoring PPG to ssess risk of dibetic complictions or crdiovsculr disese. 14 In this study, blood glucose levels were determined using stndrd glucose meter becuse of its prcticlity. All the volunteers chieved PPG levels <140 mg/dl by 2 h postprndil, which is considered to be within the norml rnge; therefore, t lest in this study, PPG would not hve given n bnorml result tht might indicte the presence of postprndil dysmetbolism. As shown in Figure 2, between-mel differences were not lrge. As expected, however, the mel with the lowest crbohydrte content (mel 2) did produce significntly lower PPG thn the other mels in our study (see Tble 6). Postprndil insulin tends to mirror PPG, but cliniclly, postprndil insulin levels hve been found to predict CHD irrespective of PPG levels. For exmple, in the Pris Protective Study 15 investigting risk fctors in lrge mle popultion, 2 h postlod insulin level ws mjor independent predictor of CHD deth, wheres impired glucose tolernce ws not. Similrly, the Helsinki Policemen Study 16 showed tht the predictive vlue of high plsm insulin for CHD ws lso independent of other risk fctors, including blood glucose levels; 1 nd 2 h postprndil levels were better ssocited with CHD events thn fsting insulin. In this study, postprndil insulin levels t the 2 h time point reveled significnt between-mel differences, which ppered to be relted to crbohydrte content of the mixed mels. As seen in Figure 3, mel 2 (with the lowest crbohydrte content) produced the lowest postprndil insulin, while mel 4 (with the highest crbohydrte content) produced the highest postprndil insulin. The sttisticl nlysis, which compred ech mel to ll other mels for every individul who hd consumed both mels in piring, found significntly more norml or optiml insulin levels t 2 h postprndil fter mel 2 nd significntly fewer norml or optiml levels fter mel 4 (see Tbles 2 nd 3). Protein nd ft content of the mels (see Tble 1) hd miniml effects in the mounts relisticlly found in mels tht people et, s hs been noted in nother mel study looking t typicl food consumption rther thn rtificilly high glucose or ft lods. 17 In light of these results, lrger-scle studies my determine tht simple blood spot collection 2 h fter eting typicl brekfst mel my constitute convenient test to help identify crdiometbolic risk in individuls whose fsting insulin levels re norml. Protocols could be estblished to determine suitble cutoffs, such s the norml or optiml clssifictions tht reveled between-mel differences in this study. Such individuls who hve bnorml levels t 2 h my be encourged to modify their diets to mitigte risk of postprndil dysmetbolism nd potentil for developing crdiovsculr disese or dibetes. Triglyceride levels t 2 h did not differ significntly between mels, s shown in Figure 4 nd Tbles 4 nd 5; however, other studies in the literture hve found tht triglyceride levels pek round 4 h postprndil, nd in our subjects, the triglyceride levels were still rising t the 2.5 h time point. In this study, crried out in helthy volunteers during their regulr working dy, we noted the potentil for low complince when ttempting to study subjects for longer thn 3 h fter brekfst mel without further consumption of beverges or sncks. In lrger study looking t 4 h smple collection, subjects should be closely monitored to ensure tht they do not consume nything during this time. Postprndil triglycerides hve been found to be n independent risk fctor of crdiovsculr disese in lrger popultion studies nd were most useful when levels were determined round 4 h postprndil. 10 Lrger-scle studies tking dvntge of the convenience of blood spot collection my determine whether routine blood spot triglycerides test t 4 h fter typicl brekfst my help identify individuls t risk. This study, lthough smll, demonstrted the use of DBS test to ssess the presence of postprndil dysmetbolism in mbulnt subjects fter vriety of brekfst mel types. As in the generl popultion, proportion of our subjects (5/19) met the criteri for metbolic syndrome. While the overll conclusions regrding the postprndil responses to different mels were similr for metbolic syndrome nd nonmetbolic syndrome subjects, it would 242

8 be interesting to conduct lrger study of dietry influences on postprndil metbolism in metbolic syndrome. The convenience nd prcticlity of DBS collection pves the wy for the possibility of lrge-scle studies, in vriety of popultions, of the impct of dietry hbits on risk of metbolic syndrome, dibetes, nd crdiovsculr disese, which would not be prcticl using trditionl venipuncture blood collection. Conclusions This study demonstrtes the convenience nd simplicity of using DBSs to ssess mrkers of postprndil dysmetbolism in n mbulnt group of subjects fter consuming vriety of brekfst mels. The results of this smll study demonstrted significnt differences in postprndil insulin responses fter vriety of typicl brekfst mels in people without dibetes, suggesting higher risk of postprndil dysmetbolism fter consumption of mixed mels with high overll crbohydrte content. Lrger-scle or popultion studies of postprndil dysmetbolism using the convenience of blood spot collection could result in the development of routine test tht cn be crried out t home to help monitor risk. This methodology would lso fcilitte the study of the effects of dietry or therpeutic regimens implemented to tret dysmetbolism in people t risk. Acknowledgments: The uthors thnk Dnielle Moore of ZRT Lbortory for her diligent work in orgnizing the mels nd volunteers nd for helping with blood spot collection, Myr Turmn nd Wendy Norris of ZRT Lbortory for conducting the lbortory ssys, nd Willim Gregory, Ph.D., of the Helfgott Reserch Institute, Portlnd, OR, for his expert sttisticl nlyses. References: 1. O Keefe JH, Bell DS. Postprndil hyperglycemi/hyperlipidemi (postprndil dysmetbolism) is crdiovsculr risk fctor. Am J Crdiol. 2007;100(5): O Keefe JH, Gheewl NM, O Keefe JO. Dietry strtegies for improving post-prndil glucose, lipids, inflmmtion, nd crdiovsculr helth. J Am Coll Crdiol. 2008;51(3): Kolovou GD, Angnostopoulou KK, Dsklopoulou SS, Mikhilidis DP, Cokkinos DV. Clinicl relevnce of postprndil lipemi. Curr Med Chem. 2005;12(17): Vn Hees AM, Sris WH, Dlling-Thie GM, Hul GB, Mrtinez JA, Oppert JM, Stich V, Astrup A, Arner P, Sørensen TI, Blk EE. Fsting nd postprndil remnnt-like prticle cholesterol concentrtions in obese prticipnts re ssocited with plsm triglycerides, insulin resistnce, nd body ft distribution. J Nutr. 2008;138(12): Shim WS, Kim SK, Kim HJ, Kng ES, Ahn CW, Lim SK, Lee HC, Ch BS. Decrement of postprndil insulin secretion determines the progressive nture of type-2 dibetes. Eur J Endocrinol. 2006;155(4): Albrrk AI, Luzio SD, Chssin LJ, Plyle RA, Owens DR, Hovork R. Associtions of glucose control with insulin sensitivity nd pncretic bet-cell responsiveness in newly presenting type 2 dibetes. J Clin Endocrinol Metb. 2002;87(1): Krbulut A, Iltumur K, Toprk N, Tuzcu AK, Kr IH, Kpln A, Aksu Y. Insulin response to orl glucose loding nd coronry rtery disese in nondibetics. Int Hert J. 2005;46(5): Bltli M, Korkmz ME, Kiziltn HT, Muderris IH, Ozin B, Anrt R. Assocition between postprndil hyperinsulinemi nd coronry rtery disese mong non-dibetic women: cse control study. Int J Crdiol. 2003;88(2-3): Nordestgrd BG, Benn M, Schnohr P, Tybjerg-Hnsen A. Nonfsting triglycerides nd risk of myocrdil infrction, ischemic hert disese, nd deth in men nd women. JAMA. 2007;298(3): Bnsl S, Buring JE, Rifi N, Mor S, Scks FM, Ridker PM. Fsting compred with nonfsting triglycerides nd risk of crdiovsculr events in women. JAMA. 2007;298(3): S, S, Zv D. Crdiometbolic risk fctors ssessed by finger stick dried blood spot method. J Dibetes Sci Technol. 2008;2(2): Grundy SM, Brewer HB Jr, Cleemn JI, Smith SC Jr, Lenfnt C, Americn Hert Assocition, Ntionl Hert, Lung, nd Blood Institute. Definition of metbolic syndrome: report of the Ntionl Hert, Lung, nd Blood Institute/Americn Hert Assocition conference on scientific issues relted to definition. Circultion. 2004;109: Ribeiro-Filho FF, Fri AN, Kohlmnn NE, Znell MT, Ferreir SR. Two-hour insulin determintion improves the bility of bdominl ft mesurement to identify risk for the metbolic syndrome. Dibetes Cre. 2003;26(6): Americn Dibetes Assocition. Postprndil blood glucose. Dibetes Cre. 2001;24(4): Fontbonne AM, Eschwège EM. Insulin nd crdiovsculr disese. Pris Prospective Study. Dibetes Cre. 1991;14(6): Pyörälä K, Svolinen E, Kukol S, Hpkoski J. Plsm insulin s coronry hert disese risk fctor: reltionship to other risk fctors nd predictive vlue during 9 1/2-yer follow-up of the Helsinki Policemen Study popultion. Act Med Scnd Suppl. 1985;701: Wolever TM, Yng M, Zeng XY, Atkinson F, Brnd-Miller JC. Food glycemic index, s given in glycemic index tbles, is significnt determinnt of glycemic responses elicited by composite brekfst mels. Am J Clin Nutr. 2006;83(6):