Background
Methods
Study participants
Data collection
Assessment of sunlight exposure and temperature
Outcomes
Statistical methods
Results
Exploratory and confirmatory samples
Characteristic | Exploratory sample | Confirmatory sample | P-value |
---|---|---|---|
Quartiles of insolation, n (%) | |||
1st (12327 to 15565 KJ/m2/day) | 2207 (24.8%) | 2236 (25.2%) | |
2nd (15565 to 16724 KJ/m2/day) | 2180 (24.5%) | 2263 (25.5%) | 0.22 |
3rd (16724 to 17724 KJ/m2/day) | 2223 (25.0%) | 2220 (25.0%) | |
4th (17724 to 22733 KJ/m2/day) | 2276 (25.6%) | 2168 (24.4%) | |
Maximum Temperature, n (%) | |||
1st quartile (8.5 to 17.8°C) | 2206 (24.8%) | 2237 (25.2%) | |
2nd quartile (17.8 to 21.7°C) | 2247 (25.3%) | 2198 (24.7%) | 0.82 |
3rd quartile (21.7 to 24.0°C) | 2224 (25.0%) | 2217 (24.9%) | |
4th quartile (24.0 to 31.7°C) | 2209 (24.9%) | 2235 (25.1%) | |
SBP, mean mmHg (SD) | 126.5 (16.4) | 126.4 (16.0) | 0.49 |
Cholesterol, mean mg/dL (SD) | 195.0 (38.2) | 194.3 (37.8) | 0.25 |
LDL, mean mg/dL (SD) | 116.8 (34.0) | 116.3 (33.9) | 0.34 |
HDL, mean mg/dL (SD) | 53.3 (16.3) | 53.2 (16.1) | 0.24 |
Ln CRP, mean mg/dL (SD) | 0.77 (1.16) | 0.75 (1.18) | 0.17 |
Hypertensive, n (%) | 4847 (54.5%) | 4760 (53.6%) | 0.19 |
Dyslipidemia, n (%) | 4778 (53.8%) | 4718 (53.1%) | 0.36 |
High CRP risk category, n (%) | 3511 (39.5%) | 3449 (38.8%) | 0.3377 |
Impaired kidney function, n (%) | 737 (8.3%) | 722 (8.1%) | 0.68 |
Systolic blood pressure
Insolation exposure | SBP (mmHg) | Total cholesterol (mg/dL) | LDL (mg/dL) | HDL (mg/dL) | LnCRP (mg/dL) |
---|---|---|---|---|---|
Quartiles of insolation exposure | |||||
Exploratory analyses – Unadjusted | |||||
1st vs 4th quartile |
3.5 (2.6, 4.5)
| 1.5 (−0.7, 3.8) | 2.4 (0.5, 4.4) |
−1.3 (−2.2, −0.3)
|
0.0 (−0.1, 0.0)
|
2nd vs 4th quartile |
2.3 (1.4, 3.3)
| 0.3 (−1.9, 2.6) | 0.8 (−1.2, 2.8) |
−2.0 (−2.9, −1.0)
|
0.1 (0.0, 0.1)
|
3rd vs 4th quartile |
1.9 (0.9, 2.9)
| 0.2 (−2.0, 2.5) | 0.4 (−1.6, 2.3) |
−0.9 (−1.8, 0.1)
|
0.1 (0.0, 0.2)
|
Exploratory analyses – Fully adjusted | |||||
1st vs 4th quartile |
2.3 (0.8, 3.8)
| −3.1 (−6.6, 0.4) | −1.1 (−4.2, 2.0) |
−2.7 (−4.2, −1.2)
| 0.0 (−0.1, 0.1) |
2nd vs 4th quartile |
1.9 (0.8, 3.1)
| −2.1 (−4.8, 0.7) | −0.7 (−3.1, 1.7) |
−2.0 (−3.2, −0.9)
| 0.1 (0.0, 0.2) |
3rd vs 4th quartile |
1.4 (0.4, 2.4)
| −0.8 (−3.1, 1.5) | −0.5 (−2.6, 1.6) |
−0.6 (−1.6, 0.3)
| 0.1 (0.0, 0.1) |
Confirmatory analyses – Unadjusted | |||||
1st vs 4th quartile |
3.3 (2.3, 4.2)
| N/A | N/A |
−0.2 (−1.1, 0.8)
|
−0.1 (−0.1, 0.0)
|
2nd vs 4th quartile |
1.7 (0.8, 2.6)
| N/A | N/A |
−1.8 (−2.8, −0.9)
|
0.0 (−0.1, 0.1)
|
3rd vs 4th quartile |
1.8 (0.9, 2.6)
| N/A | N/A |
−0.6 (−1.6, 0.3)
|
0.1 (0.0, 0.2)
|
Confirmatory analyses – Fully adjusted | |||||
1st vs 4th quartile | 1.6 (−0.5, 3.7) | N/A | N/A |
−1.5 (−3.0, −0.1)
| 0.0 (−0.1, 0.1) |
2nd vs 4th quartile | 1.1 (−0.5, 2.7) | N/A | N/A |
−2.1 (−3.2, −0.9)
| 0.0 (−0.1, 0.1) |
3rd vs 4th quartile | 1.4 (−1.0, 1.7) | N/A | N/A |
−0.5 (−1.4, 0.6)
| 0.0 (0.0, 0.1) |
Low insolation exposure | |||||
<5th vs ≥5th percentile | |||||
Exploratory analyses - Unadjusted |
2.4 (0.8, 3.9)
| 0.5 (−3.1, 4.1) | 1.3 (−2.0, 4.5) | −1.0 (−2.6, 0.5) |
−0.2 (−0.3, −0.1)
|
Exploratory analyses – Fully adjusted |
2.5 (1.0, 4.1)
| −0.4 (−4.1, 3.3) | 0.9 (−2.4, 4.2) |
−1.7 (−3.2, −0.1)
| −0.1 (−0.2, 0.0) |
Confirmatory analyses - Unadjusted | 1.1 (−0.4, 2.7) | N/A | N/A | −0.1 (−1.6, 1.5) |
−0.1 (−0.2, 0.0)
|
Confirmatory analyses – Fully adjusted | 0.6 (−1.7, 2.9) | N/A | N/A | 0.0 (−1.7, 1.6) | −0.1 (−0.2, 0.0) |
High insolation exposure | |||||
<95th vs ≥95th percentile | |||||
Exploratory analyses - Unadjusted | 0.3 (−1.3, 1.9) | −1.9 (−5.5, 1.8) | 0.4 (−2.8, 3.6) |
−3.6 (−5.1, −2.0)
| 0.0 (−0.1, 0.1) |
Exploratory analyses – Fully adjusted | 0.2 (−1.4, 1.7) | −2.7 (−6.3, 1.0) | 0.0 (−3.2, 3.2) |
−2.7 (−4.2, −1.2)
| −0.1 (−0.2, 0.0) |
Confirmatory analyses - Unadjusted | N/A | N/A | N/A |
−1.7 (−3.3, −0.2)
| N/A |
Confirmatory analyses – Fully adjusted | N/A | N/A | N/A | −1.5 (−3.1, 0.0) | N/A |
Quartiles of insolation exposure | SBP (mmHg) | ||
---|---|---|---|
Blacks | Whites | p-value | |
Exploratory analyses – Unadjusted | |||
1st vs 4th quartile |
4.7 (3.2, 6.1)
|
2.4 (1.1, 3.6)
| |
2nd vs 4th quartile |
1.4 (−0.1, 3.0)
|
3.1 (1.9, 4.3)
|
0.0005
|
3rd vs 4th quartile |
1.3 (−0.2, 2.8)
|
2.1 (0.9, 3.3)
| |
Exploratory analyses – Fully adjusted | |||
1st vs 4th quartile |
3.8 (2.8, 5.6)
|
1.4 (−0.2, 3.1)
| |
2nd vs 4th quartile |
1.1 (−0.5, 2.7)
|
2.4 (1.0, 3.8)
|
0.0012
|
3rd vs 4th quartile |
1.2 (−0.2, 2.7)
|
1.5 (0.2, 2.7)
| |
Confirmatory analyses – Unadjusted | |||
1st vs 4th quartile |
4.6 (3.2, 6.1)
|
1.9 (0.7, 3.1)
| |
2nd vs 4th quartile |
1.8 (0.2, 3.3)
|
1.9 (0.7, 3.0)
|
0.0058
|
3rd vs 4th quartile |
1.7 (0.2, 3.2)
|
1.7 (0.5, 2.9)
| |
Confirmatory analyses – Fully adjusted | |||
1st vs 4th quartile | 1.7 (−0.7, 4.1) | 1.6 (−0.9, 4.1) | |
2nd vs 4th quartile | 0.6 (−1.5, 2.6) | 1.6 (−0.4, 3.7) | 0.5855 |
3rd vs 4th quartile | −0.3 (−2.3, 1.6) | 1.0 (−0.8, 2.8) |
Total cholesterol, LDL, and HDL
Continuous C-reactive protein
Hypertension
Insolation exposure | Hypertension | Dyslipidemia | High CRP | Impaired kidney |
---|---|---|---|---|
Quartiles of insolation exposure | ||||
Exploratory analyses – Unadjusted | ||||
1st vs 4th quartile | 1.1 (0.9, 1.2) | 1.0 (0.9, 1.1) |
0.9 (0.8, 1.1)
| 0.8 (0.7, 1.0) |
2nd vs 4th quartile | 1.0 (0.9, 1.2) | 1.1 (1.0, 1.2) |
1.1 (0.9, 1.2)
| 0.9 (0.8, 1.2) |
3rd vs 4th quartile | 1.2 (1.0 (1.3) | 1.0 (0.9, 1.2) |
1.2 (1.0, 1.3)
| 0.9 (0.7, 1.1) |
Exploratory analyses – Fully adjusted | ||||
1st vs 4th quartile | 1.2 (0.9, 1.4) | 0.9 (0.8, 1.1) | 1.1 (0.9, 1.3) | 0.8 (0.6, 1.2) |
2nd vs 4th quartile | 1.0 (0.9, 1.2) | 1.0 (0.9, 1.2) | 1.2 (1.0, 1.4) | 0.9 (0.7, 1.2) |
3rd vs 4th quartile | 1.1 (0.9, 1.2) | 1.0 (0.9, 1.1) | 1.1 (1.0, 1.3) | 0.9 (0.7, 1.2) |
Confirmatory analyses – Unadjusted | ||||
1st vs 4th quartile | N/A | N/A | 1.0 (0.8, 1.1) | N/A |
2nd vs 4th quartile | N/A | N/A | 1.0 (0.9, 1.1) | N/A |
3rd vs 4th quartile | N/A | N/A | 1.1 (1.0, 1.2) | N/A |
Confirmatory analyses – Fully adjusted | ||||
1st vs 4th quartile | N/A | N/A | 1.1 (0.9, 1.4) | N/A |
2nd vs 4th quartile | N/A | N/A | 1.0 (0.8, 1.2) | N/A |
3rd vs 4th quartile | N/A | N/A | 1.0 (0.9, 1.2) | N/A |
Low insolation exposure | ||||
<5th vs ≥5th percentile | ||||
Exploratory analyses - Unadjusted | 1.0 (0.8, 1.2) | 1.1 (0.9, 1.3) |
0.8 (0.6, 0.9)
| 0.8 (0.6, 1.2) |
Exploratory analyses – Fully adjusted | 1.2 (1.0, 1.5) | 1.2 (1.0, 1.5) | 0.9 (0.7, 1.1) | 0.8 (0.6, 1.3) |
Confirmatory analyses - Unadjusted | N/A | N/A | 0.9 (0.7, 1.1) | N/A |
Confirmatory analyses – Fully adjusted | N/A | N/A | 0.9 (0.7, 1.2) | N/A |
High insolation exposure | ||||
<95th vs ≥95th percentile | ||||
Exploratory analyses - Unadjusted | 1.0 (0.8, 1.2) | 1.2 (1.0, 1.5) | 1.0 (0.9, 1.3) | 0.8 (0.6, 1.1) |
Exploratory analyses – Fully adjusted | 0.9 (0.8, 1.2) | 1.2 (0.9, 1.4) | 0.9 (0.7, 1.1) | 0.8 (0.6, 1.2) |
Confirmatory analyses - Unadjusted | N/A | N/A | N/A | N/A |
Confirmatory analyses – Fully adjusted | N/A | N/A | N/A | N/A |