Estimated seasonal phase as calendar days and amplitude for cardiovascular disease risk factors, adjusted for sex and age, with median and IQR, and p value for test of seasonality at population and individual levels, the Tromsø Study 1979–2008
| Variable (subjects/observations) units | Phase, median (IQR; days) | Amplitude, median (IQR) | Population, p value | Individual, p Value |
| SBP (37 998/91 739), mm Hg | March 27 (February 6 to April 25; 78) | 1.03 (0.64–1.80) | <0.001 | <0.001 |
| DBP (37 998/91 739), mm Hg | January 14 (December 13 to February 2; 51) | 0.54 (0.39–0.84) | <0.001 | <0.001 |
| HR (34 680/74 998), bpm | November 12 (October 11 to December 12; 62) | 0.72 (0.56–1.01) | <0.001 | <0.001 |
| Weight (37 918/84 545), kg | January 19 (December 25 to May 4; 130) | 0.54 (0.30–0.88) | <0.001 | <0.001 |
| Cholesterol (37 986/92 641), mmol/l | November 27 (October 26 to December 23; 58) | 0.13 (0.10–0.19) | <0.001 | <0.001 |
| Triglycerides (37 982/92 626), % | September 21 (August 25 to October 8; 44) | 3.0 (2.3–4.1) | <0.001 | <0.001 |
| HDL cholesterol (37 971/92 576), mmol/l | December 10 (December 1 to December 19; 18) | 0.031 (0.029–0.037) | <0.001 | <0.001 |
| CRP (16 292/31 936), % | May 23 (March 8 to August 5; 150) | 6.4 (3.3–11.2) | 0.131 | <0.001 |
| CRP if CRP<10 mg/l (15 909/30 557), % | June 18 (April 17 to September 19; 155) | 7.4 (3.9–12.1) | 0.131 | <0.001 |
| Fibrinogen (16 450/25 421), g/l | April 29 (April 19 to May 7; 18) | 0.055 (0.050–0.063) | <0.001 | <0.001 |
| Fibrinogen if CRP <10 mg/l (13 884/16 816), g/l | February 22 (January 29 to May 20; 112) | 0.045 (0.027–0.079) | 0.005 | <0.001 |
CRP, C reactive protein; DBP, diastolic blood pressure; HDL, high-density lipoprotein; HR, heart rate; SBP, systolic blood pressure.