Plasma Fatty Acids, Not Dietary Fatty Acids, Associated with Obesity in Four Ethnic Minority Groups Unique to Southwest China: A Cross-Sectional Study

Figures & data

Figure 1 Inclusion process of enrolled people.

Abbreviations: OB, obesity group (BMI ≥28.0 kg/m²); NB, normal-BMI group (18.5≤ BMI <24.0 kg/m²).

Table 1 Baseline Characteristics of Participants

Clinical Features	Hani (n = 44)	Bulang (n = 60)	Wa (n= 70)	Naxi (n = 158)
Age, years	50 (39, 58)	43 (30, 53)	46 (34, 54)	51 (45, 60)^b,c
Male gender, n (%)	20 (45.4)	24 (40.0)	20 (28.6)^a,b	48 (30.4)^a,b
Low education level, n (%)	27 (61.4)	32 (53.3)	42 (60.0)	52 (32.9)^a,b,c
Low physical activity, n (%)	7 (15.9)	2 (3.3)^a	8 (11.4)^b	32 (20.3)^b,c
Peasantry, n (%)	37 (84.1)	57 (95.0)^a	67 (94.3)^a	147 (93.0)^a
Smoking, n (%)	16 (36.4)	18 (30.0)^a	19 (27.1)^a	30 (19.0)^a,b,c
Alcohol use, n (%)	22 (50.0)	31 (51.7)	29 (41.4)	30 (19.0)^a,b,c
SBP, mm Hg	118.0 (110.0, 133.3)	119.7 (110.0, 136.5)*	122.7 (111.3, 132.0)	125.5 (118.3, 139.2)*
DBP, mm Hg	80.0 (75.3, 87.8)	80.0 (73.7, 85.6)*	80.0 (74.7, 85.6)	82.5 (75.9, 91.3)*
FPG, mmol/L	4.9 (4.4, 5.4)	4.7 (4.0, 5.3)	4.6 (4.2, 5.3)*	4.7 (4.2, 5.4)*
Plasma TG, mmol/L	1.4 (1.0, 1.9)	1.8 (1.2, 3.3)*,^a	2.7 (1.6, 4.1)*,^a	1.9 (1.5, 2.4)^a,c
Plasma TC, mmol/L	4.8 (3.8, 5.5)	5.2 (4.4, 6.0)*,^a	5.3 (4.7, 6.0)^a	5.0 (4.2, 5.3)^c
Plasma LDL-C, mmol/L	2.6 (2.1, 3.1)*	3.2 (2.6, 3.7)^a	3.1 (2.6, 3.6)^a	2.7 (2.1, 3.2)^b,c
Plasma HDL-C, mmol/L	1.3 (1.1, 1.5)	1.3 (1.1, 1.5)	1.3 (1.1, 1.5)*	1.3 (1.2, 1.5)

Notes: Total n = 332. Data are presented as mean (standard deviation) for parametric variables; median (interquartile range) for non-parametric variables.*Compared with the NB group of the same minority, the difference was statistically significant. ^aCompared with Hani, the difference was statistically significant; ^bCompared with Bulang, the difference was statistically significant; ^cCompared with Wa, the difference was statistically significant.

Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; FPG, fasting plasma glucose; TG, triglycerides, TC, total cholesterol; LDL-C, low-density lipoprotein; HDL-C, high-density lipoprotein.

Figure 2 Comparison of fatty acids among four minorities.

Notes: (A and B), comparison of dietary fatty acids among four minorities; (C and D), comparison of plasma fatty acids among four minorities. (B and D), in the same fatty acid comparison, the darker the color, the higher the content; and the different color, the difference between the groups was statistically significant; the same color indicates no significant difference between groups. P value < 0.05 was considered statistically significant.

Table 2 Dietary Fatty Acids of four Minorities (% of Total Fatty Acids)

DFAs	Hani People (n = 44)		Bulang People (n = 60)		Wa People (n = 70)		Naxi People (n = 158)
	NB (n = 22)	OB (n = 22)	NB (n = 30)	OB (n = 30)	NB (n = 35)	OB (n = 35)	NB (n = 79)	OB (n = 79)
C12:0	0.3 (0.3)	0.4 (0.3)	0.8 (0.4, 1.6)	0.8 (0.5, 1.3)	1.0 (0.5, 1.7)	0.9 (0.4, 2.1)	0.5 (0.3, 0.8)	0.5 (0.3, 1.3)
C14:0	1.1 (0.8)	1.3 (0.5)	1.9 (1.3, 4.5)	2.3 (1.6, 3.7)	2.3 (1.5, 3.8)	2.5 (1.4, 4.6)	1.0 (0.7, 1.7)	0.9 (0.6, 1.4)
C16:0	18.8 (10.0, 24.9)	22.8 (17.0, 29.7)	35.0 (18.4, 62.2)	41.7 (30.5, 57.1)	38.8 (29.5, 63.8)	39.3 (24.0, 72.2)	16.5 (12.8, 27.5)	15.9 (10.7, 21.3)
C17:0	0.2 (0.1)	0.2 (0.2)	0.3 (0.1, 0.7)	0.2 (0.1, 0.5)	0.5 (0.3, 0.9)	0.4 (0.2, 1.0)	0.3 (0.2, 0.5)	0.3 (0.2, 0.6)
C18:0	10.0 (5.2, 13.0)	11.3 (8.4, 14.8)	15.4 (8.1, 28.7)	16.4 (13.4, 26.0)	16.7 (10.0, 25.9)	16.1 (10.9, 22.9)	8.4 (6.5, 14.5)	8.0 (5.3, 11.5)
C20:0	0.4 (0.4)	0.4 (0.2)	0.8 (0.7)	1.0 (0.9)	0.8 (0.4, 1.0)	0.7 (0.5, 1.2)	0.7 (0.5, 1.0)	0.9 (0.6, 1.6)*
C22:0	0.5 (0.8)	0.5 (0.7)	1.1 (1.1)	1.5 (1.5)	0.8 (0.5, 1.7)	1.3 (0.6, 1.7)	1.9 (1.2, 2.9)	2.3 (1.7, 3.2)
C16:1	2.4 (1.5)	2.8 (1.2)	7.9 (8.0)	7.3 (6.9)	6.6 (4.2, 9.6)	6.4 (3.7, 11.3)	0.5 (0.3, 0.8)	0.3 (0.2, 0.6)*
C17:1	0.1 (0.0)	0.1 (0.0)	0.2 (0.1, 0.7)	0.1 (0.1, 0.4)	0.2 (0.1, 0.4)	0.3 (0.2, 0.6)	0.1 (0.0, 0.1)	0.0 (0.0, 0.1)*
C18:1	35.3 (17.8, 48.2)	43.1 (30.6, 57.6)	60.4 (36.3, 111.2)	70.8 (56.5, 107.8)	78.3 (47.2, 112.8)	76.0 (45.4, 119.4)	36.9 (28.2, 56.6)	35.7 (24.8, 47.1)
C20:1	0.5 (0.5)	0.7 (0.5)	0.8 (0.6)	1.0 (0.5)	0.6 (0.5, 1.1)	1.0 (0.6, 1.5)*	1.5 (1.0, 2.4)	1.8 (1.3, 2.7)
C22:1	0.0 (0.0, 0.6)	0.2 (0.0, 2.5)	2.0 (0.2, 4.5)	3.3 (1.2, 5.7)	1.5 (0.3, 5.5)	5.1 (1.3, 8.0)*	10.3 (6.3, 16.0)	11.1 (8.9, 17.7)
C16:2	0.1 (0.1, 0.3)	0.3 (0.2, 0.4)	0.3 (0.1, 0.8)	0.5 (0.3, 0.9)	0.4 (0.2, 0.6)	0.4 (0.2, 0.6)	0.2 (0.1, 0.3)	0.2 (0.1, 0.3)
C18:2	11.6 (6.2, 19.6)	13.2 (9.1, 18.8)	48.7 (42.0)	61.9 (58.6)	41.2 (30.6, 85.9)	49.9 (31.1, 76.2)	17.5 (11.9, 26.1)	18.5 (11.9, 24.8)
C18:3	1.0 (0.5, 2.0)	1.2 (0.7, 1.7)	5.6 (4.6)	6.3 (5.3)	4.4 (3.0, 7.2)	5.6 (4.0, 8.7)	3.4 (2.4, 4.7)	4.0 (3.0, 5.5)
C20:2	0.1 (0.1)	0.1 (0.1)	0.2 (0.1, 0.5)	0.2 (0.1, 0.4)	0.2 (0.1, 0.4)	0.2 (0.1, 0.4)	0.2 (0.1, 0.3)	0.2 (0.1, 0.5)*
C20:4	0.1 (0.1)	0.1 (0.1)	0.7 (0.7)	0.6 (0.5)	0.4 (0.3, 1.0)	0.3 (0.2, 0.7)	0.1 (0.1, 0.2)	0.1 (0.1, 0.2)

Notes: Data are presented as mean (standard deviation) for parametric variables; median (interquartile range) for non-parametric variables. *A significant difference (P < 0.05) between NB and OB within a given people group.

Abbreviations: OB, obesity group (BMI ≥28.0 kg/m²); NB, normal-BMI group (18.5≤ BMI <24.0 kg/m²); DFAs, dietary fatty acids.

Table 3 Plasma Fatty Acids of four Minorities (mg/L)

PFAs	Hani People (n = 44)		Bulang People (n = 60)		Wa People (n = 70)		Naxi People (n = 158)
	NB (n = 22)	OB (n = 22)	NB (n = 30)	OB (n = 30)	NB (n = 35)	OB (n = 35)	NB (n = 79)	OB (n = 79)
C14:0	1.0 (0.5)	1.3 (0.5)	0.6 (0.5, 1.2)	1.1 (0.8, 1.8)	0.9 (0.6, 1.3)	1.5 (0.8, 2.0)*	1.0 (0.7)	1.2 (0.5)*
C15:0	0.4 (0.4, 0.4)	0.4 (0.4, 0.4)	0.2 (0.1)	0.2 (0.1)	0.2 (0.1)	0.2 (0.1)	0.2 (0.2, 0.3)	0.3 (0.0, 0.3)
C16:0	14.0 (4.6)	17.1 (4.9)*	13.5 (12.3, 16.3)	18.1 (15.1, 22.4)*	14.3 (11.1, 18.7)	19.9 (14.2, 24.8)*	14.1 (11.9, 17.3)	15.5 (12.5, 17.8)
C17:0	0.5 (0.1)	0.5 (0.1)	0.3 (0.3, 0.4)	0.4 (0.3, 0.5)	0.4 (0.1)	0.5 (0.1)	0.4 (0.3, 0.5)	0.4 (0.4, 0.5)*
C18:0	14.8 (3.6)	16.6 (3.3)	16.9 (14.8, 19.4)	18.5 (14.9, 21.7)	18.5 (7.0)	20.2 (6.5)	15.8 (12.7, 17.9)	13.0 (11.4, 15.0)*
C20:0	0.4 (0.1)	0.4 (0.1)	0.5 (0.2, 0.5)	0.3 (0.1, 0.5)	0.4 (0.2)	0.4 (0.1)	0.5 (0.5, 0.5)	0.5 (0.5, 0.5)*
C22:0	0.3 (0.3, 0.3)	0.3 (0.3, 0.3)	0.4 (0.0, 0.5)	0.1 (0.0, 0.5)	0.3 (0.2)	0.3 (0.1)	0.5 (0.5, 0.5)	0.5 (0.5, 0.5)
C16:1 n-7	2.1 (1.1)	2.9 (1.6)	1.5 (1.2, 2.9)	3.0 (2.4, 4.3)*	2.7 (2.0)	3.8 (1.9)*	2.0 (1.4)	2.1 (1.1)
C18:1 n-9t	0.3 (0.3, 0.3)	0.3 (0.3, 0.3)	0.3 (0.2)	0.3 (0.2)	0.2 (0.2)	0.2 (0.2)	0.4 (0.4, 0.4)	0.4 (0.4, 0.5)
C18:1 n-9c	18.2 (10.0)	23.9 (11.4)	16.0 (12.1, 22.6)	28.8 (20.9, 43.9)*	19.5 (13.2, 26.7)	32.0 (20.5, 40.5)*	25.6 (15.0)	28.5 (14.5)
C20:1 n-9	0.4 (0.3, 0.4)	0.4 (0.3, 0.6)	0.7 (0.4, 0.9)	0.5 (0.3, 0.9)	0.8 (0.6, 0.9)	0.7 (0.6, 1.1)	1.0 (0.8, 1.6)	0.9 (0.8, 1.4)
C22:1	0.3 (0.0, 0.3)	0.3 (0.0, 0.4)	0.1 (0.2)	0.2 (0.2)	0.2 (0.2)	0.2 (0.1)	0.4 (0.4, 0.5)	0.4 (0.4, 0.5)
C18:2 n-6c	21.3 (6.3)	27.3 (10.2)*	22.6 (18.4, 27.1)	28.2 (23.7, 32.5)	25.8 (14.3)	27.4 (9.8)	26.7 (21.6, 33.0)	32.5 (26.1, 37.8)*
C18:3 n-6	0.7 (0.3)	0.8 (0.5)	0.6 (0.3, 0.8)	0.7 (0.4, 0.9)	0.4 (0.4)	0.4 (0.3)	0.8 (0.3)	0.9 (0.3)*
C18:3 n-3	0.7 (0.3)	0.9 (0.3)	0.7 (0.5, 1.0)	0.8 (0.5, 1.2)	0.7 (0.5, 1.1)	0.7 (0.5, 1.1)	1.5 (1.0, 2.3)	1.9 (1.4, 2.7)*
C20:2 n-6	0.7 (0.3)	0.7 (0.3)	0.6 (0.5, 0.8)	0.7 (0.6, 1.0)	0.5 (0.4, 0.7)	0.5 (0.4, 0.6)	0.7 (0.6, 0.8)	0.7 (0.6, 0.8)
C20:3 n-6	1.5 (0.3)	1.5 (0.7)	0.9 (0.8)	1.5 (0.8)*	1.2 (0.9, 1.6)	1.6 (1.2, 1.9)*	1.3 (0.5)	1.7 (0.5)*
C20:3 n-3	0.3 (0.0, 0.4)	0.4 (0.0, 0.4)	0.3 (0.0, 0.6)	0.3 (0.0, 0.6)	0.4 (0.0, 0.6)	0.4 (0.0, 0.6)	0.6 (0.6, 0.9)	0.7 (0.6, 0.9)
C20:4 n-6	6.5 (2.4)	6.5 (4.3)	4.6 (4.1)	6.6 (4.9)	5.1 (4.0, 6.9)	6.6 (5.5, 8.0)	5.5 (2.3)	6.3 (1.9)*
C20:5 n-3	0.0 (0.0, 0.6)	0.0 (0.0, 0.0)	0.1 (0.2)	0.4 (0.4)*	0.3 (0.3)	0.6 (0.3)*	0.6 (0.5)	0.9 (0.4)*

Notes: Data are presented as mean (standard deviation) for parametric variables; median (interquartile range) for non-parametric variables. *A significant difference (P < 0.05) between NB and OB within a given people group.

Abbreviations: OB, obesity group (BMI ≥28.0 kg/m²); NB, normal-BMI group (18.5≤ BMI <24.0 kg/m²); PFAs, plasma fatty acids.

Table 4 Conditional Logistic Regression Analysis of Obesity

	β	OR	95% CI	P
Hani
C16:0 (PFA)	0.270	1.310	1.028–1.669	0.029
Bulang
–	–	–	–	–
Wa
C20:3 n-6 (PFA)	1.833	6.250	1.224–31.927	0.028
C20:1 (DFA)	2.223	9.231	1.253–68.016	0.029
Naxi
C18:0 (PFA)	−0.238	0.788	0.681–0.912	0.001
ALL
C20:3 n-6 (PFA)	0.925	2.523	1.350–4.716	0.004
C20:5 n-3 (PFA)	1.285	3.614	1.412–9.251	0.007

Abbreviations: PFA, plasma fatty acid; DFA, dietary fatty acid; OR, odds ratio.

Figure 3 Canonical correlation analysis of dietary fatty acids and plasma fatty acids.

Notes: (A–C), canonical correlation analysis of dietary fatty acids and plasma fatty acids in the Bulang people; (D–F), canonical correlation analysis of dietary fatty acids and plasma fatty acids in the Naxi people; (G–I), canonical correlation analysis of dietary fatty acids and plasma fatty acids in all people. r, canonical correlation coefficient; P < 0.05 were considered significant.