Gender differences in the protective effects of green tea against amnestic mild cognitive impairment in the elderly Han population

Figures & data

Table 1 Characteristics of the participants in aMCI group and NC group based on gender

Characteristics	Male (n=965)				Female (n=1,166)
	aMCI (n=155)	NC (n=810)	t or X^2	P-value	aMCI (n=284)	NC (n=882)	t or X^2	P-value
Age (years)	73.88±7.68	70.32±7.60	5.15	0.000*	74.55±8.60 (n=272)	69.74±7.36 (n=873)	8.32	0.000*
Education (years)	7.76±4.97	9.98±6.35	3.89	0.000*	4.12±4.21 (n=253)	7.98±5.07 (n=840)	12.14	0.000*
Tea consumption (%)	48.4 (n=75)	62.1 (n=504)	10.26	0.001*	21.1 (n=60)	26.8 (n=236)	3.632	0.057
Green tea habit (%)	44.5 (n=69)	53.9 (n=437)	4.64	0.031*	18.31 (n=52)	21.09 (n=186)	1.02	0.312
Black tea habit (%)	6.5 (n=10)	7.7 (n=62)	0.27	0.602	2.82 (n=8)	5.22 (n=46)	2.80	0.094
Oolong tea habit (%)	2.96 (n=2)	1.29 (n=24)	0.82	0.364	0.7 (n=2)	1.25 (n=11)	0.19	0.665
Smoking history (%)	51.6 (n=80)	54.0 (n=437)	0.29	0.593	6.3 (n=18)	4.6 (n=40)	1.45	0.229
Drinking history (%)	41.2 (n=63)	37.4 (n=302)	0.77	0.380	4.0 (n=11)	4.0 (n=35)	0.00	0.983
Hypertension history (%)	38.1 (n=59)	45.4 (n=368)	2.863	0.091	45.8 (n=130)	46.9 (n=414)	0.12	0.732
Heart disease history (%)	16.1 (n=25)	18.3 (n=148)	0.406	0.524	22.9 (n=65)	26.0 (n=229)	1.08	0.299
Endocrine and metabolic disease history (%)	18.7 (n=29)	20.4 (n=165)	0.223	0.636	23.2 (n=66)	29.0 (n=256)	3.60	0.058
MMSE	24.49±4.70 (n=153)	27.33±2.86 (n=810)	7.22	0.000*	21.32±5.97 (n=284)	26.40±3.91 (n=880)	13.43	0.000*
MoCA	19.34±5.75 (n=154)	23.69±4.40 (n=804)	8.91	0.000*	15.30±5.98 (n=282)	22.17±5.69 (n=878)	17.42	0.000*

Notes: P-value was calculated from independent t-test for continuous variables and chi-square test for dichotomous variables;

* P<0.05; tea habit means at least three cases of tea drinking a week. Drinking history means an average alcohol consumption of >20 g/day.

Abbreviations: aMCI, amnestic mild cognitive impairment; MMSE, Mini-Mental State Examination; MoCA, Montreal Cognitive Assessment; NC, normal control.

Table 2 The protective effects of three types of tea from aMCI in gender- and age-specific groups

	Green tea			Black tea			Oolong tea
	OR	95% CI	P-value	OR	95% CI	P-value	OR	95% CI	P-value
All male (n=965)	0.657	0.46–0.93	0.019*	0.738	0.37–1.49	0.397	0.390	0.09–1.68	0.206
55–69 years (n=473)	0.376	0.20–0.70	0.002*	0.174	0.02–1.31	0.090	0.000	0.000	0.999
70–79 years (n=360)	0.802	0.64–1.79	0.802	0.193	0.74–4.36	0.193	0.934	0.22–5.31	0.934
80 years and more (n=132)	0.652	0.28–1.51	0.318	0.279	0.03–2.37	0.242	0.000	0.000	0.999
All female (n=1,166)	0.82	0.58–1.16	0.261	0.52	0.24–1.12	0.093	0.60	0.13–2.72	0.504
55–69 years (n=581)	1.06	0.62–1.80	0.840	0.35	0.08–1.48	0.152	0.99	0.11–8.58	0.992
70–79 years (n=396)	0.96	0.56–1.65	0.890	0.65	0.18–2.36	0.512	0.49	0.06–4.18	0.513
80 years and more (n=189)	0.43	0.18–1.03	0.057	0.84	0.18–3.90	0.828	None	None	None

Notes: Multiple logistic regression was used to estimate the OR and 95% CI of tea consumption and the risk of aMCI, adjusted for educational levels; none indicates no participants; aged >80 years had the habit of oolong tea consumption;

* P<0.05.

Abbreviation: aMCI, amnestic mild cognitive impairment.

Table 3 The correlative factors of cognitive performance (MoCA and MMSE) for different genders

	MoCA (male, n=965)				MoCA (female, n=1,166)
	B	SE	Adjusted B	P-value	B	SE	Adjusted B	P-value
Age	−0.221	0.018	−0.344	0.000*	−0.260	0.018	−0.315	0.000*
Education	0.309	0.022	0.390	0.000*	0.714	0.028	0.569	0.000*
Green tea	0.996	0.279	0.101	0.000*	0.155	0.327	0.010	0.635
Black tea	−1.001	0.519	−0.054	0.054	0.011	0.619	0.000	0.986
Oolong tea	0.411	0.815	0.014	0.614	−0.938	1.207	−0.016	0.437
	MMSE (male, n=965)				MMSE (female, n=1,166)
	B	SE	Adjusted B	P-value	B	SE	Adjusted B	P-value
Age	−0.146	0.013	−0.336	0.000*	−0.192	0.015	−0.302	0.000*
Education	0.187	0.016	0.348	0.000*	0.514	0.023	0.530	0.000*
Green tea	0.742	0.196	0.110	0.000*	0.054	0.271	0.004	0.842
Black tea	−0.051	0.365	−0.004	0.889	0.184	0.514	0.008	0.720
Oolong tea	−0.026	0.572	−0.001	0.964	0.174	1.002	0.004	0.862

Notes: Multiple linear regressions were used to estimate the correlation between factors and cognitive performance.

* P<0.05.

Abbreviations: MMSE, mini-mental state examination; MoCA, montreal cognitive assessment; SE, standard error.