Effects of ^–3.7α Deletion and Sickle-Cell Trait on Ventilatory and Hemodynamic Responses to Maximum Exercise in Young Saudi Females

Figures & data

Table 1 Comparison of Body Indices and Hematological, Ventilatory, and Hemodynamic Parameters Between the Control Group and Sickle-Cell Trait (SCT) Subjects, and Between the Control Group and Subjects with 3.7 Rightward Deletion (^−3.7α₂/α₁α₂) Using Independent-Sample Student’s t-test

	Control Group (α1α2/α1α2 and non-SCT), mean ± SD (Interquartile Range), n=42	SCT, mean ±SD (Interquartile Range), n=5	P-value	^−3.7α2/α1α2, mean ± SD (Interquartile Range), n=28	P-value
Weight, kg	52.26±5.12 (6.5)	55.0±5.9 (3.9)	0.606	53.428±5.25 (8.4)	0.376
BMI	21.18±1.53 (2.52)	22.1±1.7 (1.73)	0.461	21.43±1.68 (1.72)	0.547
RBC count ×10^6	4.31±0.52 (0.42)	4.8±0.6 (0.13)	0.068	4.52±0.74 (0.64)	0.163
Hb, g/dL	11.4±0.9 (0.875)	10.9±0.1 (0.6)	0.267	10.7±1.65* (1.2)	0.020
Hct, %	36.22±3.10 (4.225)	36.5±3.1 (2.8)	0.870	34.42±5.33 (4.575)	0.080
MCH, pg	26.41±2.19 (2.9)	23.1±3.0** (0.8)	0.004	23.89±4.76** (5.225)	0.005
MCHC, g/dL	31.98±3.58 (1.925)	30.0±1.1 (1)	0.220	31.05±3.14 (1.775)	0.269
RDW, %	15.32±4.67 (2.925)	13.5±1.7 (0.1)	0.397	15.06±3.67 (2.3)	0.810
MCV, fl	86.49±11.88 (8.8)	77.0±7.8* (6.1)	0.045	72.42±13.45** (15)	0.00005
HbF, %	0.61±1.23 (0.3)	0.7±0.5 (0.8)	0.898	0.29±0.23 (0.125)	0.182
HbA2, %	2.72±0.24 (0.3)	3.2±0.2 (0)	0.067	2.66±0.69 (0.45)	0.778
Serum ferritin, µg/L	19.55±20.88 (10.745)	16.5±12.7 (22.55)	0.318	20.05±18.89 (20.3)	0.924
Serum iron, µg/L	71.54±37.64 (59.5)	73.0±34.7 (37.1)	0.383	56.82±30.76 (40)	0.107
TIBC, µmol/L	312.66±76.53 (78.65)	354.5±44.7 (72.6)	0.332	312.99±68.51 (107.3)	0.986
Ventilation, L/min (VE)	60.84±11.31 (16)	64.5±17.0 (18.9)	0.468	56.09±11.02 (16.8)	0.055
Tidal volume, L	1.275±0.196 (0.298)	1.4±0.2 (0.065)	0.380	1.29±0.18 (0.212)	0.714
Respiratory frequency	48.11±7.70 (8.2)	45.9±12.1 (7.3)	0.918	43.14±7.67* (13.9)	0.013
VO2max, mL/min	1,513.73±206.16 (221)	1,467.8±186.58 (263)	0.640	1,355.45±177.94** (230)	0.004
VO2max, mL/min.kg	28.41±4.19, (5.25)	29.7±3.9 (1.64)	0.929	26.63±3.0 (3.74)	0.087
CO2 production (VCO2), mL/min	1560.59±263.61 (315)	1,622.0±432.8 (94)	0.859	1,501.16±286.00 (370)	0.393
Respiratory exchange ratio, VCO2/VO2	1.29±0.09 (0.08)	1.3±0.1 (0.05)	0.975	1.33±0.10 (0.12)	0.230
Anerobic threshold, mL/min	825.39±423.28 (261)	879.2±293.8 (204)	0.555	700.4±185.78 (345)	0.168
Anerobic threshold, mL/min.kg	15.76±7.76 (4.35)	16.1±5.2 (5.55)	0.509	13.076±3.22 (5.1)	0.105
Resting heart rate (beats/min)	97.02±15.46 (16)	94.0±14.8 (17)	0.640	96.88±12.97 (13)	0.960
Resting systolic blood pressure (mmHg)	97.83±10.4 (11)	100.8±10.6 (4)	0.211	103.52±12.38* (18)	0.049
Resting diastolic blood pressure (mmHg)	57.68±8.91 (11)	59.8±8.6 (12)	0.105	60.12±8.22 (9)	0.271
Maximum heart rate (beats/min)	181.61±6.93 (11)	179.2±8.8 (3)	0.585	183.44±7.18 (8)	0.308
Systolic blood pressure (mmHg) at VO2max	143.9±14.73 (21)	141.6±9.5 (12)	0.813	143.90±14.73 (15)	0.321
Diastolic blood pressure (mmHg) at VO2max	80.54±13.31 (17)	77.2±16.7 (26)	0.985	81.76±19.15 (17)	0.761
Postexercise heart rate after 3 minutes’ recovery (beats/min)	164.27±134.19 (22)	146.2±10.6 (10)	0.747	143.16±12.81 (18)	0.437
Postexercise diastolic blood pressure (mmHg)	57.09±8.22 (12)	60±13.66 (14)	0.239	54.22±7.18 (10)	0.165
Postexercise systolic blood pressure (mmHg)	109.71±13.89 (20)	123±13.51* (22)	0.037	111.30±11.1 (18.5)	0.318

Notes: *P<0.05, **P<0.01.

Abbreviations: RBC, red blood cell; Hb, hemoglobin; Hct, hematocrit; MCH, mean corpuscular hemoglobin; MCHC, MCH concentration; RDW, red cell–distribution width; MCV, mean cell volume; TIBC, total iron-binding capacity; VO_2max, maximum O₂ uptake.

Table 2 β-globin Gene Variations in the Study Subjects

	Mutations	Control Group (α1α2/α1α2 and non SCT), n=42	SCT, n=5	^−3.7α2/α1α2, n=28
β-globin mutations	β^0 or β^+ mutations	Hetero HBB:c370A>C (n=1); Hetero HBB:c431T>A (n=2); Hetero HBB:c435G>A (n=3)	Hetero HBB:c20A>T (n=5)	Hetero HBB:c93–21G>A (n=1); Hetero HBB:c431T>A (n=1);
	Intronic	Homo c315+74T>G (n=10); Hetero c315+74T>G (n=14); c316–156_316-155insATTTMTGCATAYAAAT (n=1); Hetero c59A>C (n=1); c316–183_316-168delCTGCATATAAATATT (n=2); c316–158_316-157insATATTTMTRCATAYAA (n=1); Hetero c(315+26T>G) (n=1)	Hetero c315+74T>G (n=3); Homo c315+16G>C (n=3); c316–183_316-168delCTGCATATAAATATTT, (n=1); c316–156_316-155insATTTMTGCATAYAAAT(n=1).	Homo c315+74T>G (n=10); Hetero c315+74T>Gn=9); Homo c315+16G>C (n=18); c316–156_316-155insATYTCTGCATATAART (n=1); Hetero c315+81C>T(n=2); Hetero c(92+5G>C (n=1); Hetero c316–49C>G (n=1); Hetero HBB:c294C>T (n=1) (synonymous variant)
α-globin mutations		α1α2/α1α2 (n=42)	^−3.7α2/α1α2 (n=2); α1α2/α1α2 (n=2); α1-^4.2/α1α2 (n=1)	^−3.7α2/α1α2 (n=28)