Table 3. Distribution of mtDNA haplogroups in female subjects of different age groups.

Haplogroups	Longevity	Elderly	Middle-aged	p(L vs. E)	p(L vs. M)	p-trend
D4	78(21.7%)	118(16.4%)	57(15.8%)	0.034	0.045	0.025
B4a	6(1.7%)	27(3.8%)	15(4.2%)	0.060	0.046	0.045
M9	0(0%)	14(1.9%)	6(1.7%)	0.008	0.014	0.032
N9	19(5.3%)	51(7.1%)	31(8.6%)	0.256	0.079	0.082