Hypothyroidism and the risk of lower extremity arterial disease

Figures & data

Table 1 Baseline characteristics of subjects

Variable	All subjects (n = 1143)		Males (n = 535)		Females (n = 608)
	Cases (n = 614)	Controls (n = 529)	Cases (n = 299)	Controls (n = 236)	Cases (n = 315)	Controls (n = 293)
Hypothyroidism	63 (10.3%)	61 (11.5%)	44 (14.8%)	12 (5.1%)*	19 (6.0%)	49 (16.7%)*
Diabetes mellitus	388 (63.2%)	99 (18.7%)*	188 (62.9%)	36 (15.3%)*	200 (63.5%)	63 (21.5%)*
Hypertension	528 (86.0%)	317 (59.9%)*	269 (90.0)%	133 (56.4%)*	259 (82.2%)	184 (62.8%)*
Dyslipidemia	332 (54.1%)	202 (38.2%)*	163 (54.5%)	91 (38.6%)*	169 (53.7%)	111 (37.9%)*
Ischemic heart disease	386 (62.9%)	102 (19.3%)*	171 (57.2%)	58 (24.6%)*	215 (68.3%)	44 (15.0%)*
Male gender	299 (48.7%)	236 (44.6%)	–	–	–	–
Age1	71.9 (13.1)	72.1 (7.8)	74.2 (13.2)	71.2 (7.9)*	69.8 (12.6)	72.7 (7.7)*

1 Notes: All data represent n = absolute numbers (percent of category total) except for age, where the data represent mean age (standard deviation)

* P < 0.01 for comparison between cases and controls within each group.

Table 2 Unadjusted and adjusted odds ratios of lower extremity arterial disease for study variables

Variable	Unadjusted OR1 (95% CI)	Adjusted OR2 (95% CI)
Hypothyroidism
All	0.88 (0.61, 1.28)	n/a3
Male	–	2.85 (1.31, 6.16)*
Female	–	0.26 (0.13, 0.52)*
Diabetes mellitus	7.46 (5.67, 9.80)*	5.18 (3.82, 7.03)*
Hypertension	4.11 (3.08, 5.47)*	2.35 (1.66, 3.32)*
Dyslipidemia	1.93 (1.52, 2.44)*	0.88 (0.64, 1.17)
Ischemic heart disease	7.09 (5.40, 9.29)*	5.32 (3.91, 7.24)*
Age (per 10 years)	1.01 (0.91, 1.13)	0.97 (0.85, 1.11)
Male gender	1.18 (0.93, 1.49)	–

1 Notes: Unadjusted odds ratios were calculated using the following method: OR, Odds of having lower extremity arterial disease in exposure group/Odds of having lower extremity arterial disease in nonexposure group

2 Adjusted odds ratios were obtained from a multivariate logistic regression model that included all variables in this table

3 For hypothyroidism, an adjusted odds ratio is listed for males and females separately. This is because a significant interaction between gender and hypothyroidism was found (P < 0.001), demonstrating the effect modification that gender had on the relationship between hypothyroidism and lower extremity arterial disease.

* P < 0.05.

Abbreviations: CI, confidence intervals; OR, odds ratio

Table 3 Unadjusted and adjusted odds ratios of lower extremity arterial disease for study variables by gender

Variable	Males		Females
	Unadjusted OR1 (95% CI)	Adjusted OR2 (95% CI)	Unadjusted OR1 (95% CI)	Adjusted OR2 (95% CI)
Hypothyroidism	3.23 (1.67, 6.28)**	2.65 (1.19, 5.89)*	0.32 (0.18, 0.56)**	0.22 (0.11, 0.46)**
Diabetes mellitus	9.41 (6.15, 14.4)**	8.04 (4.94, 13.1)**	6.35 (4.43, 9.11)**	3.99 (2.60, 6.13)**
Hypertension	6.94 (4.40, 11.0)**	4.33 (2.54, 7.39)**	2.74 (1.89, 3.98)**	1.35 (0.83, 2.20)
Dyslipidemia	1.92 (1.36, 2.72)**	0.91 (0.58, 1.43)	1.92 (1.39, 2.66)**	0.86 (0.56, 1.33)
Ischemic heart disease	4.10 (2.82, 5.96)**	2.72 (1.74, 4.26)**	12.2 (8.17, 18.1)**	11.4 (7.17, 18.2)**
Age (per 10 years)	0.79 (0.67, 0.92)**	1.43 (1.16, 1.77)**	1.31 (1.12, 1.53)**	0.68 (0.56, 0.83)**

1 Notes: Unadjusted odds ratios were calculated using the following method: OR, Odds of having lower extremity arterial disease in exposure group/Odds of having lower extremity arterial disease in nonexposure group

2 Adjusted odds ratios were obtained from a multivariate logistic regression model that included all variables in this table.

* P < 0.05

** P < 0.01.

Abbreviations: CI, confidence intervals; OR, odds ratio