Effect of AMY1 copy number variation and various doses of starch intake on glucose homeostasis: data from a cross-sectional observational study and a crossover meal study

Table 3 Fasting plasma glucose and BMI across AMY1 CN groups and in strata of starch intake tertiles

	AMY1 CN groups				Per AMY1 CN		Starch interaction
	≤ 4	5–6	7–9	≥ 10	ß	P	ß¹	P¹	Adjusted ß²	Adjusted P²
Fasting plasma glucose (excl individuals with prediabetes)
All (n = 1608)	5.19 (5.13–5.24)	5.20 (5.16–5.25)	5.21 (5.16–5.27)	5.25 (5.19–5.31)	0.004	0.40	− 0.002	0.02	− 0.002,	0.03
Low starch < 24.9E% (n = 367)	5.17 (5.05–5.29)	5.13 (5.03–5.22)	5.20 (5.09–5.32)	5.31 (5.17–5.45)	0.017	0.06
Medium starch 24.9–29.4 E% (n = 377)	5.11 (4.98–5.23)	5.21 (5.10–5.32)	5.21 (5.09–5.34)	5.19 (5.05–5.34)	0.004	0.68
High starch > 29.4E% (n = 372)	5.24 (5.11–5.37)	5.24 (5.14–5.34)	5.16 (5.05–5.27)	5.16 (5.03–5.29)	− 0.017	0.06
ß per E% of starch³	0.005	0.006	− 0.009	− 0.009
P value²	0.43	0.08	0.09	0.14
Adjusted ß per E% of starch⁴	0.005	0.007	− 0.011	− 0.004
Adjusted P value⁴	0.42	0.07	0.05	0.47
BMI
All (n = 1764)	25.3 (24.8–25.8)	25.2 (24.8–25.6)	25.7 (25.3–26.2)	25.3 (24.7–25.9)	0.05	0.26	− 0.017	0.07	− 0.018	0.05
Low starch < 24.9E% (n = 407)	25.4 (24.2–26.6)	24.6 (23.7–25.6)	25.6 (24.5–26.8)	25.5 (24.1–26.8)	0.08	0.39
Medium starch 24.9–29.4 E% (n = 408)	24.7 (23.7–25.8)	25.1 (24.2–26.0)	26.0 (24.6–27.0)	25.8 (24.6–27.0)	0.18	0.03
High starch > 29.4E% (n = 408)	25.5 (24.5–26.6)	25.1 (24.3–25.9)	25.2 (24.3–26.1)	24.3 (23.2–25.4)	− 0.14	0.09
ß per E% of starch³	− 0.03	− 0.02	− 0.07	− 0.11
P value²	0.57	0.57	0.12	0.04
Adjusted ß per E% of starch⁴	− 0.03	0.002	− 0.06	− 0.09
Adjusted P value⁴	0.53	0.96	0.19	0.10

Values are presented as the means (95% CI) adjusted for age, sex, and ethnicity unless stated otherwise
¹Interaction AMY1 CN × starch intake, both as continuous variables, adjusted for age, sex and ethnicity (n = 1223, excluding individuals with prediabetes n = 1116)
²Interaction AMY1 CN × starch intake, both as continuous variables, adjusted for age, sex, and ethnicity, energy intake, smoking habits, and physical activity level (n = 1130, excluding individuals with prediabetes n = 1026)
³Association between starch intake (continuous) and fasting glucose or BMI in strata of AMY1 CN adjusted for age, sex, and ethnicity.
⁴Association between starch intake (continuous) and fasting glucose or BMI in strata of AMY1 CN adjusted for age, sex, ethnicity, energy intake, smoking habits, and physical activity level
AMY1, salivary α-amylase gene; CN, copy number

ISSN: 1865-3499