Association of the NEGR1 rs2815752 with obesity and related traits in Pakistani females

Figures & data

Table 1. Genotypic frequencies of the NEGR1 rs2815752 variant among gender-stratified cases (obese) and controls along with assessment of the association of the rs2815752 with obesity.

		Males				Females
Genetic model	Genotype	Cases, n (%)	Controls, n (%)	Adjusted OR (95% CI) ^a	Adjusted p-value^a	Cases, n (%)	Controls, n (%)	Adjusted OR (95% CI) ^a	Adjusted p-value^a
Co-dominant	GG	13 (12.15)	10 (9.35)		0.615	7 (8.05)	18 (20.69)		0.042^b
	GA	45 (42.06)	41 (38.32)			38 (43.68)	36 (41.76)
	AA	49 (45.79)	56 (52.34)			42 (48.28)	33 (37.93)
Pair-wise comparison	GG vs GA			0.84 (0.33, 2.13)	0.720			2.65 (0.98, 7.14)	0.054
	GG vs AA			0.67 (0.27, 1.67)	0.394			3.47 (1.28, 9.38)	0.014 ^b
Dominant	(GA + AA)	94 (87.85)	97 (90.66)	0.75 (0.31, 1.78)	0.509	80 (91.96)	69 (79.69)	3.03 (1.19, 7.72)	0.020 ^b
	GG	13 (12.15)	10 (9.35)			7 (8.05)	18 (20.69)
Recessive	AA	49 (45.79)	56 (52.34)	0.77 (0.45, 1.32)	0.342	42 (48.28)	33 (37.93)	1.75 (0.94, 3.25)	0.076
	(GG + GA)	58 (54.21)	51 (47.67)			45 (51.73)	54 (62.45)
Over-dominant	GA	45 (42.06)	41 (38.32)	1.17 (0.67, 2.02)	0.582	38 (43.68)	36 (41.76)	1.03 (0.56, 1.90)	0.916
	(GG + AA)	62 (57.94)	66 (61.69)			49 (56.33)	51 (58.62)
Adjusted h index = 0.023
Hardy–Weinberg Equilibrium (HWE):					p-value				p-value
Cases					0.597				0.689
Controls					0.584				0.177

Data represent genotype counts and percentages in parenthesis in cases and controls. Data also indicate genotypic frequencies in HWE. Association of rs2815752 with obesity in obese cases was tested using chi-square and multinomial regression for co-dominant model and binary logistic regression for other models.

^a Analysis was performed with adjustment for age. ^bAdjusted p-value <0.05 were considered statistically significant. Adjusted h index was calculated for indication of appropriate mode of inheritance.

AA: mutant homozygous genotype; CI: confidence interval; GA: heterozygous genotype; GG: wild-type homozygous genotype; OR: odds ratio.

Table 2. Assessment of the association of the NEGR1 variant rs2815752 with BMI grades in the sample population using a dominant model of inheritance.

	All (males and females)		Males		Females
	Adjusted		Adjusted		Adjusted
Genotype	OR (95% CI)	p-value	OR (95% CI)	p-value	OR (95% CI)	p-value
GA + AA	1.30 (1.01, 1.67)	0.041^a	1.12 (0.79, 1.59)	0.512	1.59 (1.10, 2.28)	0.013^a
GG	1		1		1

Ordinal regression was used to calculate parameter estimates under PLUM command. BMI grade 0 was taken for normal weight, BMI grade 1 for ‘overweight’, BMI grade 2 for ‘class I obesity’, BMI grade 3 for ‘class II obesity’, and BMI grade 4 for ‘class III obesity’.

^a p-values <0.05 were considered significant.

Table 3. Assessment of the association of the rs2815752 with obesity-related anthropometric variables in gender-stratified obese cases and controls.

Variables (unit of measurement)	Dominant model	Males			Females
		Mean (SD)	Adjusted β (95% CI)	Adjusted p-value	Mean (SD)	Adjusted β (95% CI)	Adjusted p-value (corrected)
Weight (kg)	GG	83.57 (21.20)	−0.848 (−11.139, 9.444)	0.871	62.48 (17.43)	13.102 (3.656, 22.547)	0.033^a
	GA + AA	82.72 (23.93)			75.55 (22.76)
Height (cm)	GG	171.38 (6.45)	−0.746 (−3.835, 2.342)	0.634	156.63 (6.27)	0.857 (−1.54, 3.228)	0.477
	GA + AA	170.63 (7.15)			157.50 (5.59)
BMI (kg/m^2)	GG	28.51 (7.26)	−0.163 (−3.472, 3.146)	0.923	25.43 (6.80)	5.043 (1.398, 8.688)	0.003^a
	GA + AA	28.35 (7.66)			30.46 (8.97)
WC (cm)	GG	100.33 (16.68)	0.016 (−7.952, 7.983)	0.997	92.08 (20.22)	10.907 (1.828, 19.987)	0.049^a
	GA + AA	100.35 (18.84)			102.91 (21.50)
HC (cm)	GG	107.08 (14.20)	−0.172 (−6.894, 6.550)	0.960	102.00 (12.26)	7.915 (1.623, 14.207)	0.049^a
	GA + AA	106.91 (15.65)			109.90 (15.16)
WHR	GG	0.93 (0.07)	−0.000 (−0.030, 0.030)	0.987	0.89 (0.10)	0.036 (−0.006, 0.078)	0.099
	GA + AA	0.93 (0.07)			0.93 (0.10)
Biceps SFT (mm)	GG	13.91 (8.46)	−1.426 (−5.198, 2.345)	0.457	15.39 (9.15)	4.372 (−0.343, 8.400)	0.060
	GA + AA	12.49 (8.68)			19.75 (9.48)
Triceps SFT (mm)	GG	25.09 (14.42)	−1.216 (−7.588, 5.156)	0.707	23.18 (8.54)	4.382 (0.196, 8.567)	0.060
	GA + AA	23.87 (14.63)			27.55 (10.04)
Abdominal SFT (mm)	GG	42.65 (18.48)	−2.687 (11.677, 6.302)	0.556	29.93 (12.57)	8.571 (2.445, 14.697)	0.033^a
	GA + AA	39.98 (21.24)			38.46 (15.22)
Supra-iliac SFT (mm)	GG	39.96 (16.91)	−4.700 (−13.001, 3.601)	0.266	21.71 (10.10)	5.338 (0.810, 9.866)	0.049^a
	GA + AA	35.27 (19.55)			27.02 (10.90)
Thigh SFT (mm)	GG	37.35 (24.53)	−0.893 (−11.704, 9.918)	0.871	32.72 (12.70)	6.765 (0.712, 12.818)	0.058
	GA + AA	36.45 (24.87)			39.48 (14.38)
Sub-scapular SFT (mm)	GG	26.61 (12.57)	−0.495 (−6.297, 5.307)	0.867	24.11 (11.52)	5.774 (0.194, 11.354)	0.060
	GA + AA	26.12 (13.43)			29.87 (13.37)
Forearm (mm)	GG	281.82 (27.97)	−4.182 (−18.783, 10.419)	0.573	241.86 (30.49)	13.995 (−2.116, 30.106)	0.099
	GA + AA	277.61 (33.25)			255.74 (35.66)
Percentage of body fat	GG	28.21 (10.69)	−0.997 (−5.664, 3.670)	0.674	28.35 (8.88)	3.672 (−0.421, 7.764)	0.099
	GA + AA	27.22 (10.78)			32.00 (9.86)

Association with anthropometric traits was assessed by linear regression using dominant model of inheritance. The effect sizes (β) with 95% confidence intervals and p-values were provided after adjustment for age.

^a An adjusted and corrected p-value <0.05 was considered statistically significant.

BMI: body mass index; CI: confidence interval; HC: hip circumference; SD: standard deviation; SFT: skin fold thickness; WC: waist circumference; WHR: waist-to-hip ratio.

Table 4. Assessment of the association of the rs2815752 with obesity-related metabolic variables in gender stratified obese cases and controls.

Variables (unit of measurement)	Dominant model	Males			Females
		Mean (SD)	Adjusted for age and BMI		Mean (SD)	Adjusted for age and BMI
			β (95% CI)	p-value		β (95% CI)	p-value
Systolic BP (mmHg)	GG	119.57 (11.47)	2.510 (−2.986, 8.006)	0.369	110.72 (12.50)	0.528 (−5.144, 6.200)	0.854
	GA + AA	122.01 (13.60)			116.25 (16.91)
Diastolic BP (mmHg)	GG	77.39 (9.15)	3.334 (−0.938, 7.607)	0.125	73.60 (8.10)	2.125 (−2.463, 6.712)	0.362
	GA + AA	80.65 (10.61)			77.60 (11.53)
VAI (mmol/l)	GG	3.65 (1.79)	−0.615 (−1.665, 0.435)	0.249	3.31 (2.35)	0.000 (−0.83, 0.830)	1.00
	GA + AA	3.03 (2.57)			3.60 (1.91)
LAP (mmol/l)	GG	63.87 (42.92)	−6.770 (−23.242, 9.703)	0..419	44.69 (36.35)	−2.721 (−15.016, 9.574)	0.663
	GA + AA	56.50 (50.32)			60.72 (44.02)
TyG index	GG	8.91 (0.43)	−0.250 (−0.471, −0.028)	0.027	8.55 (0.46)	−0.053 (−0.244, 0.139)	0.587
	GA + AA	8.66 (0.57)			8.59 (0.48)
FBG (mg/dl)	GG	102.26 (14.46)	−0.60 (−10.44, 9.24)	0.904	106.40 (19.28)	−4.042 (−12.947, 4.863)	0.372
	GA + AA	101.62 (24.38)			105.38 (21.30)
Insulin (µl U/ml)	GG	22.01 (9.12)	1.99 (−4.76, 8.73)	0.562	23.57 (13.57)	−1.673 (−6.935, 3.589)	0.531
	GA + AA	23.84 (17.94)			25.12 (13.12)
HOMA-IR	GG	5.61 (2.64)	0.48 (−1.57, 2.52)	0.642	6.23 (3.55)	−0.546 (−2.128, 1.035)	0.496
	GA + AA	6.05 (5.31)			6.67 (4.04)
HOMA-IS	GG	0.01 (0.02)	−0.001 (−0.004, 0.003)	0.681	0.01 (0.01)	0.001 (−0.003, 0.004)	0.623
	GA + AA	0.01 (0.01)			0.01 (0.01)
Cholesterol (mg/dl)	GG	164.74 (46.57)	−11.075 (−28.379, 6.230)	0.208	158.96 (33.16)	−8.095 (−23.264, 7.074)	0.294
	GA + AA	153.52 (39.61)			153.25 (36.40)
Triglycerides (mg/dl)	GG	158.26 (69.32)	−26.360 (−62.172, 9.452)	0.148	105.16 (41.14)	0.337 (−19.156, 19.831)	0.973
	GA + AA	131.67 (86.85)			112.76 (48.02)
HDL (mg/dl)	GG	27.43 (6.83)	1.274 (−2.235, 4.773)	0.474	31.52 (7.03)	−0.955 (−4.517, 2.606)	0.597
	GA + AA	28.71 (8.18)			30.25 (8.31)
LDL (mg/dl)	GG	103.56 (40.53)	−9.178 (−24.174, 5.818)	0.229	91.64 (31.62)	−11.629 (−24.169, 0.912)	0.069
	GA + AA	94.10 (36.30)			86.06 (31.38)
VLDL (mg/dl)	GG	31.51 (13.95)	−4.979 (−12.098, 2.140)	0.169	20.88 (8.26)	0.444 (−3.377, 4.264)	0.819
	GA + AA	26.49 (17.17)			22.64 (9.34)
CHR	GG	6.18 (1.78)	−0.486 (−1.302, 0.33)	0.241	5.54 (2.37)	−0.389 (−1.107, 0.330)	0.287
	GA + AA	5.69 (1.94)			5.33 (1.57)
CRI	GG	6.20 (1.79)	−0.579 (−1.313, 0.155)	0.121	5.28 (1.63)	−0.149 (−0.768, 0.470)	0.635
	GA + AA	5.62 (1.72)			5.29 (1.47)
AI	GG	3.84 (1.31)	−0.429 (−0.949, 0.090)	0.105	3.06 (1.22)	−0.352 (−0.791, 0.087)	0. 115
	GA + AA	3.41 (1.27)			2.94 (0.48)
TG/HDL-C	GG	6.09 (2.93)	−1.056 (−2.788, 0.677)	0.231	3.63 (2.23)	0.096 (0.763, 0.955)	0.826
	GA + AA	5.03 (4.20)			4.00 (2.02)

Association of the variant rs2815752 with metabolic traits was assessed by linear regression using dominant model of inheritance. The effect sizes (β) with 95% confidence intervals and p-values were provided after adjustment for age and BMI.

AI: Atherogenic Index; BP: blood pressure; CHR: cholesterol HDL ratio; CI: confidence interval; CRI: Coronary Risk Index; FBG: fasting blood glucose; HDL: high-density lipoprotein; HOMA-IR: homeostasis model assessment of insulin resistance; HOMA-IS: homeostasis model assessment of insulin sensitivity; LAP: lipid accumulation product; LDL: low-density lipoprotein; SD: standard deviation; TG/HDL-C: triglyceride-to-HDL-C ratio; TyG: product of triglyceride and glucose; VAI: visceral adiposity index; VLDL: very-low-density lipoprotein.

Table 5. Assessment of the association of rs2815752 variant with eating behaviour in gender-stratified obese/control pairs using a dominant model of inheritance.

Categorical traits	Response	Males					Females
		Genotype		Adjusted		p-value	Genotype		Adjusted
		GG	GA + AA	OR (95% CI)	p-value	(corrected)	GG	GA + AA	OR (95% CI)	p-value
Eating pattern	Random	19 (82.6%)	106 (55.5%)	0.25 (0.08, 0.77)	0.016	0.048^a	13 (52.0%)	89 (59.7%)	1.16 (0.48, 2.79)	0.742
	Specific	4 (17.4%)	85 (44.5%)				12 (48.0%)	60 (40.3%)
Diet unconsciousness	Yes	18 (18.3%)	145 (75.9%)	0.88 (0.31, 2.51)	0.807	0.807	15 (60.0%)	103 (69.1%)	1.44 (0.59, 3.52)	0.420
	No	5 (21.7%)	46 (24.1%)				10 (40.0%)	46 (30.9%)
TFDF	High	10 (43.5%)	66 (34.6%)	0.69 (0.27, 1.71)	0.418	0.627	7 (28.0%)	32 (21.5%)	0.48 (0.17, 1.33)	0.159
	Mod–Low	13 (56.5%)	125 (65.4%)				18 (72.0%)	117 (78.5%)

Categorical traits were assessed using logistic regression using dominant model. Parameters were adjusted for both age and BMI.

^a An adjusted and corrected p-value <0.05 was considered statistically significant.

Mod–Low: moderate to low; TFDF: tendency towards fat-dense food.