Retrospective Study
Copyright ©The Author(s) 2015.
World J Exp Med. Nov 20, 2015; 5(4): 232-243
Published online Nov 20, 2015. doi: 10.5493/wjem.v5.i4.232
Table 1 Clinical features of studied subjects
Non-Hispanic whites
Non-Hispanic blacks
Hispanics
MaleFemaleMaleFemaleMaleFemale
n137316028961057957964
Age (yr)55 ± 1954 ± 2043 ± 1742 ± 1642 ± 1741 ± 17
Systolic blood pressure (mmHg)130 ± 18125 ± 21128 ± 18122 ± 20125 ± 17120 ± 20
Diastolic blood pressure (mmHg)76 ± 1072 ± 979 ± 1174 ± 1176 ± 1071 ± 10
Body mass index (kg/m2)26.75 ± 4.6326.39 ± 5.8026.74 ± 5.3429.07 ± 7.2227.10 ± 4.6428.26 ± 5.97
Transferrin saturation (%)27.93 ± 8.3924.58 ± 8.7826.22 ± 8.1121.75 ± 8.5128.23 ± 8.5922.95 ± 8.98
Ferritin (mcg/L)176 ± 14295 ± 104215 ± 17093 ± 111169 ± 14267 ± 95
Aspartate aminotransferase (U/L)22 ± 819 ± 825 ± 1722 ± 827 ± 1623 ± 19
Alanine aminotransferase (U/L)18 ± 1114 ± 1019 ± 1318 ± 1128 ± 2421 ± 23
Gamma glutamyl transferase (U/L)35 ± 5521 ± 2046 ± 5935 ± 5546 ± 5330 ± 31
C-reactive protein (mg/dL)0.43 ± 0.760.45 ± 0.620.48 ± 0.790.53 ± 0.650.44 ± 0.840.53 ± 0.80
Table 2 Comparison of serum indices of iron by the presence or absence of diabetes mellitus
Non-Hispanic whites
Non-Hispanic blacks
Hispanics
Male
Female
Male
Female
Male
Female
DMNon-DMDMNon-DMDMNon-DMDMNon-DMDMN0n-DMDMNon-DM
n1661207137146598798106951115842132832
Iron (mcg/dL)
Mean939583878287707590988284
(95%CI)(89, 97)(94, 97)(78, 88)(86, 89)(77, 87)(85, 89)(64, 75)(74, 77)(84, 97)(96, 100)(76, 87)(82, 86)
P1NSNSNSNS0.01NS
P2NSNSNSNSNSNS
P3NSNSNSNSNSNS
Total iron binding capacity (mcg/dL)
Mean351344359360333334342353353354362377
(95%CI)(343, 359)(341, 346)(350, 368)(357, 363)(322, 344)(330, 337)(331, 352)(349, 356)(343, 363)(351, 358)(351, 373)(372, 381)
P1NSNSNSNSNS0.01
P20.002NSNSNSNSNS
P3NSNSNSNSNSNS
Transferrin saturation (%)
Mean272823252526212226282323
(95%CI)(26, 28)(28, 29)(22, 25)(24, 25)(23, 26)(26, 27)(19, 22)(21, 22)(24, 28)(27, 28)(22, 25)(22, 23)
P1NSNSNSNS0.03NS
P2NSNSNSNSNSNS
P3NSNSNSNSNSNS
Ferritin (mcg/L)
Mean228169152842822061678623015013856
(95%CI)(200, 256)(161, 177)(129, 175)(79, 89)(237, 327)(195, 218)(139, 195)(79, 92)(190, 270)(142, 159)(104, 171)(52, 60)
P1< 0.000001< 0.0000010.00003< 0.000001< 0.000001< 0.000001
P20.00010.0000030.020.00010.00001< 0.000001
P30.00020.0000030.030.00010.000004< 0.000001
Table 3 Estimated beta cell function and insulin sensitivity indices by quintile of serum ferritin concentrations
Quintile 1Quintile 2Quintile 3Quintile 4Quintile 5P1P2P3
Beta cell function by the homeostasis model assessment (%B)4
Non-Hispanic white males103 (96, 110)98 (92, 105)97 (90, 104)106 (94, 118)113 (102, 124)NSNSNS
Non-Hispanic white females117 (110, 124)115 (108, 122)109 (103, 114)111 (104, 119)110 (102, 118)NSNSNS
Non-Hispanic black males113 (104, 122)118 (107, 130)112 (103, 120)144 (107, 181)117 (106, 129)NSNSNS
Non-Hispanic black females177 (156, 197)178 (161, 196)151 (137, 164)135 (121, 150)135 (123, 147)0.000001NSNS
Hispanic males104 (91, 118)112 (101, 124)106 (97, 114)123 (106, 141)128 (116, 140)0.004NSNS
Hispanic females152 (140, 165)150 (135, 164)140 (129, 150)136 (124, 147)130 (119, 141)0.003NSNS
Insulin sensitivity by the homeostasis model assessment (%S)5
Non-Hispanic white males0.503 (0.472, 0.535)0.549 (0.513, 0.585)0.518 (0.484, 0.553)0.494 (0.463, 0.525)0.421 (0.388, 0.455)0.00005NS0.05
Non-Hispanic white females0.643 (0.610, 0.677)0.603 (0.570, 0.637)0.574 (0.539, 0.609)0.555 (0.519, 0.591)0.455 (0.420, 0.491)< 0.0000010.040.02
Non-Hispanic black males0.562 (0.516, 0.608)0.553 (0.504, 0.601)0.559 (0.512, 0.605)0.555 (0.498, 0.611)0.48 (0.426, 0.535)0.04NS0.05
Non-Hispanic black females0.510 (0.476, 0.545)0.479 (0.437, 0.522)0.453 (0.421, 0.485)0.458 (0.422, 0.495)0.379 (0.343, 0.414)0.0000010.020.007
Hispanic males0.538 (0.495, 0.580)0.533 (0.489, 0.578)0.527 (0.472, 0.583)0.524 (0.460, 0.588)0.338 (0.307, 0.370)< 0.0000010.010.007
Hispanic females0.523 (0.482, 0.563)0.535 (0.484, 0.587)0.464 (0.426, 0.502)0.444 (0.403, 0.485)0.321 (0.289, 0.352)< 0.0000010.0050.003
Insulin sensitivity by the simple QUICKI6
Non-Hispanic white males0.339 (0.336, 0.342)0.343 (0.340, 0.346)0.340 (0.336, 0.343)0.337 (0.334, 0.341)0.327 (0.323, 0.331)< 0.0000010.0080.002
Non-Hispanic white females0.352 (0.349, 0.355)0.348 (0.345, 0.351)0.345 (0.342, 0.348)0.343 (0.340, 0.346)0.33 (0.327, 0.334)< 0.0000010.000050.00001
Non-Hispanic black males0.344 (0.339, 0.348)0.342 (0.338, 0.347)0.343 (0.339, 0.348)0.341 (0.335, 0.346)0.333 (0.328, 0.338)0.0030.030.01
Non-Hispanic black females0.340 (0.336, 0.343)0.335 (0.331, 0.339)0.333 (0.329, 0.337)0.333 (0.329, 0.337)0.322 (0.317, 0.326)< 0.0000010.00060.0001
Hispanic males0.341 (0.336, 0.345)0.34 (0.336, 0.345)0.339 (0.335, 0.344)0.337 (0.332, 0.342)0.318 (0.314, 0.322)< 0.0000010.00010.00001
Hispanic females0.340 (0.336, 0.344)0.340 (0.336, 0.345)0.334 (0.330, 0.338)0.330 (0.326, 0.335)0.315 (0.310, 0.319)< 0.0000010.000030.00002
Table 4 Serum ferritin concentration and estimated insulin sensitivity indices by quintile of inflammatory marker - C-reactive protein
Quintile 1Quintile 2Quintile 3Quintile 4Quintile 5P1P2P3
Serum ferritin concentration (mcg/L)
Non-Hispanic white males142 (130, 155)157 (144, 170)179 (164, 195)201 (180, 222)201 (181, 221)< 0.0000010.0000020.000005
Non-Hispanic white females19 (18, 20)49 (48, 50)120 (116, 125)152 (134, 171)108 (95, 120)0.0000030.000030.00003
Non-Hispanic black males186 (163, 209)187 (167, 207)267 (236, 298)227 (202, 253)254 (281, 228)NSNSNS
Non-Hispanic black females90 (74, 106)79 (66, 91)77 (65, 89)102 (87, 118)115 (98, 132)0.0020.00090.001
Hispanic males150 (134, 166)157 (135, 179)161 (137, 185)157 (136, 178)172 (154, 191)NSNSNS
Hispanic females52 (44, 60)56 (48, 64)63 (53, 72)72 (60, 84)92 (68, 115)0.000010.0070.006
Insulin sensitivity by the homeostasis model assessment (%S)4
Non-Hispanic white males0.541 (0.505, 0.578)0.531 (0.500, 0.562)0.546 (0.509, 0.582)0.459 (0.425, 0.494)0.412 (0.383, 0.440)< 0.0000010.050.03
Non-Hispanic white females0.684 (0.651, 0.718)0.627 (0.592, 0.661)0.596 (0.558, 0.634)0.494 (0.461, 0.526)0.422 (0.392, 0.452)< 0.0000010.0040.004
Non-Hispanic black males0.562 (0.517, 0.607)0.572 (0.526, 0.618)0.561 (0.499, 0.623)0.549 (0.488, 0.611)0.478 (0.426, 0.530)0.05NSNS
Non-Hispanic black females0.524 (0.489, 0.558)0.524 (0.487, 0.560)0.497 (0.464, 0.530)0.404 (0.369, 0.438)0.327 (0.288, 0.365)< 0.0000010.0040.002
Hispanic males0.558 (0.507, 0.608)0.484 (0.438, 0.530)0.525 (0.472, 0.578)0.513 (0.460, 0.566)0.372 (0.334, 0.411)0.00001NSNS
Hispanic females0.538 (0.495, 0.582)0.53 (0.481, 0.579)0.471 (0.430, 0.513)0.392 (0.355, 0.429)0.353 (0.319, 0.387)< 0.000001NSNS
Insulin sensitivity by the simple QUICKI5
Non-Hispanic white males0.342 (0.339, 0.346)0.342 (0.339, 0.345)0.342 (0.339, 0.346)0.332 (0.328, 0.336)0.328 (0.325, 0.331)< 0.0000010.010.008
Non-Hispanic white females0.356 (0.354, 0.359)0.351 (0.348, 0.354)0.347 (0.343, 0.350)0.336 (0.333, 0.340)0.328 (0.324, 0.331)< 0.0000010.0040.005
Non-Hispanic black males0.345 (0.341, 0.349)0.345 (0.340, 0.349)0.341 (0.336, 0.346)0.34 (0.334, 0.345)0.332 (0.327, 0.338)0.01NSNS
Non-Hispanic black females0.341 (0.337, 0.345)0.341 (0.337, 0.345)0.339 (0.335, 0.342)0.327 (0.323, 0.331)0.314 (0.310, 0.319)< 0.0000010.0000020.000001
Hispanic males0.342 (0.338, 0.347)0.335 (0.331, 0.340)0.338 (0.333, 0.343)0.338 (0.333, 0.342)0.321 (0.317, 0.326)< 0.000001NSNS
Hispanic females0.342 (0.338, 0.346)0.34 (0.336, 0.344)0.334 (0.329, 0.338)0.325 (0.321, 0.329)0.319 (0.314, 0.323)< 0.0000010.020.03
Table 5 Serum ferritin concentration and estimated insulin sensitivity indices by quintile of aspartate aminotransferase
Quintile 1Quintile 2Quintile 3Quintile 4Quintile 5P1P2P3
Serum ferritin concentration(mcg/L)
Non-Hispanic white males148 (134, 162)154 (140, 167)180 (165, 196)170 (155, 186)228 (205, 251)< 0.000001< 0.000001< 0.000001
Non-Hispanic white females58 (51, 65)61 (55, 68)85 (76, 94)102 (91, 112)140 (122, 158)0.00040.020.02
Non-Hispanic black males175 (155, 196)203 (178, 228)197 (173, 222)227 (203, 251)267 (236, 298)0.050.0030.004
Non-Hispanic black females84 (71, 96)77 (66, 88)80 (67, 92)95 (81, 109)127 (106, 149)0.000010.0040.005
Hispanic males139 (124, 153)134 (118, 151)149 (134, 163)155 (132, 177)223 (194, 251)< 0.000001< 0.000001< 0.000001
Hispanic females47 (39, 56)49 (42, 55)59 (50, 68)79 (57, 101)101 (86, 115)< 0.0000010.000010.00002
Insulin sensitivity by the homeostasis model assessment (%S)4
Non-Hispanic white males0.491 (0.457, 0.526)0.517 (0.484, 0.550)0.497 (0.466, 0.528)0.506 (0.471, 0.541)0.478 (0.441, 0.514)NSNSNS
Non-Hispanic white females0.575 (0.544, 0.607)0.597 (0.559, 0.630)0.591 (0.554, 0.628)0.555 (0.521, 0.588)0.506 (0.470, 0.543)0.02NSNS
Non-Hispanic black males0.512 (0.465, 0.559)0.531 (0.479, 0.584)0.528 (0.486, 0.569)0.557 (0.508, 0.605)0.561 (0.499, 0.623)NSNSNS
Non-Hispanic black females0.447 (0.410, 0.484)0.452 (0.418, 0.487)0.472 (0.437, 0.506)0.461 (0.424, 0.499)0.443 (0.401, 0.485)NSNSNS
Hispanic males0.501 (0.460, 0.542)0.55 (0.495, 0.604)0.524 (0.473, 0.574)0.477 (0.424, 0.530)0.404 (0.359, 0.449)< 0.000001< 0.000001< 0.000001
Hispanic females0.472 (0.430, 0.514)0.48 (0.443, 0.516)0.468 (0.430, 0.507)0.49 (0.442, 0.539)0.374 (0.330, 0.418)0.006NSNS
Insulin sensitivity by the simple QUICKI5
Non-Hispanic white males0.337 (0.333, 0.340)0.34 (0.337, 0.343)0.338 (0.335, 0.341)0.338 (0.334, 0.342)0.334 (0.330, 0.338)NSNSNS
Non-Hispanic white females0.346 (0.343, 0.349)0.347 (0.344, 0.350)0.347 (0.343, 0.350)0.343 (0.340, 0.346)0.336 (0.332, 0.340)0.009NSNS
Non-Hispanic black males0.337 (0.332, 0.342)0.339 (0.334, 0.344)0.341 (0.337, 0.345)0.343 (0.338, 0.348)0.3417 (0.336, 0.346)NSNSNS
Non-Hispanic black females0.331 (0.327, 0.335)0.332 (0.328, 0.336)0.335 (0.332, 0.339)0.333 (0.329, 0.337)0.33 (0.326, 0.334)NSNSNS
Hispanic males0.337 (0.333, 0.342)0.342 (0.337, 0.346)0.338 (0.333, 0.343)0.333 (0.328, 0.338)0.325 (0.320, 0.329)< 0.000001< 0.000001< 0.000001
Hispanic females0.334 (0.329, 0.338)0.336 (0.332, 0.340)0.334 (0.330, 0.338)0.335 (0.331, 0.340)0.32 (0.315, 0.325)0.0001NSNS
Table 6 Serum ferritin concentration and estimated insulin sensitivity indices by quintile of gamma glutamyl transferase
Quintile 1Quintile 2Quintile 3Quintile 4Quintile 5P1P2P3
Serum ferritin concentration (mcg/L)
Non-Hispanic white males141 (125, 157)146 (131,161)174 (156, 191)179 (162, 196)227 (204, 250)< 0.000001< 0.000001< 0.000001
Non-Hispanic white females55 (48, 62)70 (61, 78)95 (81, 110)92 (77, 107)137 (121, 154)< 0.000001< 0.000001< 0.000001
Non-Hispanic black males165 (144, 187)191 (163, 219)221 (195, 247)220 (194, 246)298 (263, 333)< 0.000001< 0.000001< 0.000001
Non-Hispanic black females60 (45, 74)79 (68, 91)84 (67, 100)97 (83, 112)141 (119, 163)< 0.000001< 0.000001< 0.000001
Hispanic males105 (93, 117)137 (121, 153)152 (132, 172)173 (144, 202)240 (208, 272)< 0.000001< 0.000001< 0.000001
Hispanic females38 (30, 47)38 (32, 44)59 (47, 70)82 (70, 93)109 (90, 129)< 0.000001< 0.000001< 0.000001
Insulin sensitivity by the homeostasis model assessment (%S)4
Non-Hispanic white males0.622 (0.584, 0.659)0.521 (0.486, 0.556)0.5061 (0.465, 0.546)0.422 (0.387, 0.458)0.402 (0.367, 0.436)< 0.000001< 0.000001< 0.000001
Non-Hispanic white females0.732 (0.695, 0.769)0.648 (0.609, 0.686)0.587 (0.547, 0.626)0.48 (0.444, 0.516)0.397 (0.361, 0.433)< 0.000001< 0.000001< 0.000001
Non-Hispanic black males0.607 (0.560, 0.654)0.588 (0.522, 0.653)0.537 (0.491, 0.583)0.489 (0.429, 0.548)0.462 (0.404, 0.520)0.0001NS0.05
Non-Hispanic black females0.554 (0.515, 0.594)0.454 (0.419, 0.489)0.45 (0.409, 0.491)0.407 (0.372, 0.442)0.383 (0.332, 0.434)< 0.0000010.00020.00002
Hispanic males0.67 (0.625, 0.715)0.562 (0.486, 0.638)0.423 (0.383, 0.463)0.439 (0.376, 0.501)0.359 (0.299, 0.419)< 0.0000010.000050.000005
Hispanic females0.623 (0.569, 0.677)0.494 (0.448, 0.539)0.424 (0.381, 0.466)0.338 (0.301, 0.375)0.343 (0.298, 0.389)< 0.0000010.0000020.000003
Insulin sensitivity by the simple QUICKI5
Non-Hispanic white males0.351 (0.348, 0.354)0.341 (0.338, 0.344)0.339 (0.335, 0.342)0.328 (0.324, 0.332)0.325 (0.321, 0.330)< 0.000001< 0.000001< 0.000001
Non-Hispanic white females0.361 (0.358, 0.364)0.353 (0.350, 0.356)0.347 (0.344, 0.350)0.335 (0.332, 0.339)0.323 (0.319, 0.327)< 0.000001< 0.000001< 0.000001
Non-Hispanic black males0.349 (0.345, 0.353)0.344 (0.338, 0.350)0.342 (0.337, 0.346)0.334 (0.328, 0.339)0.331 (0.325, 0.337)< 0.0000010.010.004
Non-Hispanic black females0.345 (0.341, 0.348)0.334 (0.330, 0.338)0.332 (0.328, 0.337)0.327 (0.323, 0.332)0.321 (0.315, 0.326)< 0.000001< 0.000001< 0.000001
Hispanic males0.356 (0.352, 0.360)0.341 (0.335, 0.347)0.330 (0.325, 0.334)0.329 (0.323, 0.334)0.318 (0.312, 0.324)< 0.000001< 0.000001< 0.000001
Hispanic females0.351 (0.346, 0.355)0.338 (0.334, 0.342)0.329 (0.325, 0.334)0.318 (0.313, 0.323)0.316 (0.311, 0.322)< 0.000001< 0.000001< 0.000001
Table 7 Serum ferritin concentration and estimated insulin sensitivity indices by quintile of alanine aminotransferase
Quintile 1Quintile 2Quintile 3Quintile 4Quintile 5P1P2P3
Serum ferritin concentration (mcg/L)
Non-Hispanic white males147 (132, 162)169 (153, 185)168 (152, 183)177 (159, 194)220 (200, 241)< 0.000001< 0.000001< 0.000001
Non-Hispanic white females71 (63, 79)71 (61, 82)86 (77, 95)95 (84, 107)123 (107, 139)0.050.020.02
Non-Hispanic black males168 (147, 189)187 (165, 210)201 (177, 225)247 (219, 275)267 (238, 296)0.010.000050.00005
Non-Hispanic black females80 (67, 92)79 (68, 89)87 (73, 100)98 (81, 114)120 (100, 140)0.000030.0000040.000005
Hispanic males128 (113, 143)128 (116, 140)142 (126, 157)172 (144, 200)229 (206, 253)< 0.000001< 0.000001< 0.000001
Hispanic females42 (35, 49)70 (48, 93)57 (49, 65)64 (55, 73)101 (87, 116)< 0.0000010.0000090.000009
Insulin sensitivity by the homeostasis model assessment (%S)4
Non-Hispanic white males0.551 (0.517, 0.584)0.544 (0.511, 0.578)0.512 (0.476, 0.549)0.483 (0.448, 0.518)0.399 (0.370, 0.429)< 0.000001< 0.000001< 0.000001
Non-Hispanic white females0.634 (0.602, 0.666)0.628 (0.591, 0.664)0.583 (0.546, 0.622)0.55 (0.519, 0.582)0.429 (0.395, 0.463)0.000020.0040.002
Non-Hispanic black males0.63 (0.576, 0.684)0.576 (0.522, 0.630)0.564 (0.514, 0.615)0.478 (0.423, 0.524)0.44 (0.397, 0.482)0.000020.0030.003
Non-Hispanic black females0.527 (0.490, 0.563)0.498 (0.462, 0.534)0.462 (0.424, 0.500)0.427 (0.389, 0.465)0.363 (0.330, 0.396)< 0.000001< 0.000001< 0.000001
Hispanic males0.635 (0.569, 0.700)0.57 (0.525, 0.615)0.48 (0.430, 0.530)0.448 (0.410, 0.486)0.324 (0.295, 0.352)< 0.000001< 0.000001< 0.000001
Hispanic females0.55 (0.509, 0.591)0.528 (0.484, 0.571)0.468 (0.427, 0.509)0.409 (0.365, 0.452)0.331 (0.295, 0.368)< 0.0000010.0000030.000002
Insulin sensitivity by the simple QUICKI5
Non-Hispanic white males0.344 (0.341, 0.347)0.343 (0.339, 0.346)0.339 (0.335, 0.342)0.335 (0.332, 0.339)0.326 (0.322, 0.329)< 0.000001< 0.000001< 0.000001
Non-Hispanic white females0.352 (0.349, 0.355)0.35 (0.347, 0.345)0.346 (0.342, 0.349)0.343 (0.340, 0.346)0.327 (0.324, 0.331)0.0000010.00050.0002
Non-Hispanic black males0.349 (0.344, 0.354)0.344 (0.339, 0.349)0.343 (0.338, 0.348)0.335 (0.330, 0.339)0.33 (0.326, 0.335)0.000050.010.009
Non-Hispanic black females0.341 (0.337, 0.345)0.338 (0.334, 0.342)0.333 (0.329, 0.337)0.33 (0.326, 0.334)0.321 (0.316, 0.325)< 0.000001< 0.000001< 0.000001
Hispanic males0.348 (0.343, 0.353)0.345 (0.341, 0.349)0.333 (0.328, 0.338)0.332 (0.328, 0.336)0.317 (0.313, 0.321)< 0.000001< 0.000001< 0.000001
Hispanic females0.343 (0.339, 0.347)0.34 (0.336, 0.344)0.334 (0.330, 0.338)0.327 (0.323, 0.331)0.315 (0.311, 0.320)< 0.000001< 0.000001< 0.000001