Walking behaviour and glycemic control in type 2 diabetes: seasonal and gender differences-Study design and methods

Table 1 Existing studies addressing seasonal variation in glycemic control.

	Design	Number	Women (%)	Location	Winter A1C (%)	Summer A1C (%)	Winter-summer decline in A1C (%)
LETTER
Carney et al, 2000 [12]	Retrospective cohort study using clinic records	2,080	Not reported	Northumberland (United Kingdom)	8.4	7.7	0.6 to 0.7 in women only
Asplund, 1997 [11]	Retrospective cohort study using clinic records	800	Not reported	Sweden	7.61	7.23	0.38
Ishii et al, 2001 [8]	Prospective cohort study with monthly A1C	39	69	Fukushima province, Japan	6.96 ± 0.9	6.42 ± 0.65	0.54
Sohimiya et al [9]	Prospective cohort study with monthly A1C	11	0	Japan	6.65 ± 0.12	6.25 ± 0.21	0.40
ARTICLE
Chen et al, 2004* [10]	Prospective cohort study	110	25	Taiwan	7.53 ± 1.37	7.31 ± 1.29	0.21 ± 0.94%
Tseng et al, 2005 [13] Temp (°C):	Retrospective cohort study using database	285,705 veterans. Tests:	2.2	United States, various areas	8	7.8
>10		117,665					0.07
4.4 to 10		204,001					0.08
0 to 4.4		159,485					0.24
-6.7 to 0		229,239					0.16
-15 to -6.7		77,885					0.13

*In contrast to other studies which assessed a winter-summer difference, this study was concerned with a late winter (February) vs. pre-winter (November) difference.

ISSN: 1475-2840