Death and infection frequencies
Males are dying at a higher frequency than females on a global scale. It is not expected that males would succumb to COVID-19 at a higher frequency than females; however, when compared to a 50% expected death frequency and a 50% expected infection frequency, it was found that New York reported a significant p-value and an expected probability greater than 0.50 for both male infection and male death by COVID-19 (Table 1a). Three states were found to have a significant p-value and an expected probability greater than 0.50 for male infections by COVID-19: New Jersey, Utah, and South Dakota (Table 1b). Twelve states were found to have a significant p- value and an expected probability greater than 0.50 for male deaths by COVID-19 when compared to 50% expected probability: Arizona, Colorado, Florida, Illinois, Indiana, Michigan, North Carolina, Ohio, Pennsylvania, Virginia, Washington, and Wisconsin (Table 1c).
Table 1c- Statewide COVID-19 binomial testing results for male deaths that reported a significant p value and an expected probability greater than 0.50
State
|
Chi Square Statisticfor Male Death
|
P Value for MaleDeath
|
n, the totalnumber of
deaths
|
Arizona
|
6.3404
|
0.0118
|
131
|
Colorado
|
32.22
|
1.377e-08
|
669
|
Florida
|
48.976
|
2.591e-12
|
820
|
Illinois
|
23.203
|
1.457e-06
|
944
|
Indiana
|
18.948
|
1.344e-05
|
466
|
Michigan
|
183.22
|
1.505e-10
|
2093
|
North Carolina
|
18.916
|
1.366e-05
|
131
|
Ohio
|
14.46
|
0.0001432
|
389
|
Pennsylvania
|
12.057
|
0.000516
|
702
|
Virginia
|
5.1911
|
0.0227
|
293
|
Washington
|
5.5657
|
0.01832
|
652
|
Wisconsin
|
4.508
|
0.03374
|
230
|
Using global health 5050, it was discovered that 51 countries reported either male deaths or male infections. Forty-three countries reported male infection rates. Out of those 43 countries, 12 countries were found to have a significant p value and an expected probability greater than 0.50 for both male infection and male death by COVID-19. These countries included: Thailand, The Philippines, Greece, Dominican Republic, China, Ecuador, Peru, Mexico, Iran, Pakistan, India, and Indonesia (Table 2a). Six countries had a significant p-value and an expected probability greater than 0.50 for male infections by COVID-19. However, these countries did not report death data aggregated by sex. These countries include Japan, Singapore, Panama, Algeria, Bangladesh, and Chile (Table 2b). Twenty countries had a significant p-value and an expected probability greater than 0.50 for male deaths by COVID-19 (Table 2c). These data denote out of 43 countries reporting death frequencies for males, 32 have a frequency higher than 0.50. In Greece, Dominican Republic, The Netherlands, Thailand, and Romania the male frequency of death when compared to male infections was more than twice the frequency found for female deaths when compared to female infections. In all countries tested that reported male infections and male death frequencies, all but India and Pakistan had male death frequencies compared to male infections at least 1.5 times higher than female death frequencies when compared to female infections (Supplemental Table 1).
Table 2a- Global COVID-19 binomial testing results for both male infections and male deaths that reported a significant p value and an expected probability greater than 0.50
Country
|
Chi squarestatistic formale
infection
|
P value formaleinfection
|
Chi squarestatistic formale death
|
P value formale death
|
n, thetotalnumber
of deaths
|
Thailand
|
10.541
|
0.001167
|
18.451
|
1.743e-05
|
48
|
Philippines
|
23.749
|
1.097e-06
|
56.635
|
5.246e-14
|
437
|
Greece
|
31.306
|
2.204e-08
|
26.726
|
2.344e-07
|
116
|
Dominican Republic
|
31.77
|
1.736e-08
|
79.054
|
< 2.2e-16
|
235
|
China
|
22.37
|
2.249e-06
|
1352.96
|
< 2.2e-16
|
2114
|
Ecuador
|
328.15
|
< 2.2e-16
|
89.435
|
< 2.2e-16
|
507
|
Peru
|
940.32
|
< 2.2e-16
|
94.162
|
< 2.2e-16
|
445
|
Mexico
|
243.23
|
< 2.2e-16
|
123.75
|
< 2.2e-16
|
857
|
Iran
|
293.82
|
< 2.2e-16
|
27.637
|
1.463e-07
|
853
|
Pakistan
|
2842.8
|
< 2.2e-16
|
52.25
|
4.887e-13
|
209
|
India
|
1099.2
|
< 2.2e-16
|
23.488
|
1.257e-06
|
111
|
Indonesia
|
308.16
|
< 2.2e-16
|
100.18
|
< 2.2e-16
|
773
|
Table 2c- Global COVID-19 binomial testing results for male deaths that reported a significant p value and an expected probability greater than 0.50
Country
|
Chi square statisticfor male death
|
P value for maledeath
|
n, the totalnumber of
deaths
|
France
|
511.92
|
< 2.2e-16
|
12798
|
Malaysia
|
29.267
|
6.307e-08
|
87
|
England and Wales
|
500.21
|
< 2.2e-16
|
10335
|
Scotland
|
18.855
|
1.41e-05
|
962
|
United States of
|
589
|
< 2.2e-16
|
24555
|
America Brazil
|
91.873
|
< 2.2e-16
|
2086
|
Denmark
|
11.988
|
0.0005354
|
370
|
The Netherlands
|
126.88
|
< 2.2e-16
|
3916
|
Italy
|
1799.6
|
< 2.2e-16
|
19996
|
Belgium
|
6.8528
|
0.00885
|
4283
|
Spain
|
494.56
|
< 2.2e-16
|
12364
|
Switzerland
|
38.426
|
5.686e-10
|
1186
|
Colombia
|
14.818
|
0.0001184
|
189
|
Australia
|
4.0896
|
0.04315
|
71
|
Republic of Ireland
|
6.86
|
0.008815
|
686
|
Germany
|
112.67
|
< 2.2e-16
|
4401
|
Sweden
|
34.594
|
4.062e-09
|
1765
|
Austria
|
8.9376
|
0.002794
|
456
|
Romania
|
48.53
|
3.253e-12
|
619
|
Argentina
|
17.28
|
3.226e-05
|
192
|
Role of single nucleotide polymorphisms in sex related disease outcomes
Globally it was determined there is a significant difference in SNP occurrence for males and females for the ACE2 receptor (Welch’s p-value <.001, df = 129, F=70.58). To control for potential type I errors, Benjamini & Hochberg False Discovery Rate (FDR) analysis indicated 987 pairs with significant differences (q-value <0.05). The 4 SNPs analyzed were averaged for males and females across populations. Males at higher risk for severity of disease would be males with SNPs for alternate alleles causing increased expression of the ACE2 receptor displayed in green, noted as Male1 (Figure 1, Supplemental Table 3). Males are found in all populations to have greater than 50% of the population containing the alternate alleles. Males with the largest SNP occurrence are found in African populations as well as in the African American population, ASW. This finding may contribute to increased death seen in the United States among the African American population. In most Asian countries, only the alternate alleles are found for both male and female populations. Males with the ancestral allele, yellow, noted as Male0, (Figure 1, Supplemental Table 3), which would lead to decreased ACE2 expression, are not found in abundance globally (<50% in all populations) indicating male populations have increased expression of the ACE2 receptor. Females across some populations have only the alternate allele, in dark blue noted as Female11, which increases ACE2 expression (Figure1, Supplemental Table 3). These populations include African populations and their descendants such as ASW, Asian populations, and African Caribbeans in Barbados, Peruvians, Gujarati Indian, and those in the United States with Mexican Ancestry. These populations may be at increased risk of death for female populations as they have females homozygous for the alternate allele. European populations and the United States population CEU, which represents European ancestry, contain females with a much higher level of heterozygosity, shown in blue, noted as Female 01, meaning they contain one ancestral and one alternate allele (Figure 1, Supplemental Table 3). Other populations with a higher proportion of heterozygous females would be African populations and Puerto Ricans, Columbians, and Peruvians. Though they contain the alternate allele, these females may be protected in a subset of their cells due to X-inactivation. Females who are homozygous for the ancestral allele (light blue, noted as Female00), meaning they do not contain an alternate allele, are found in the European populations; CEU from the United States (representing European descent), those from the United States with Mexican Ancestry and African Ancestry , Columbians, Puerto Ricans and in very small amounts the African populations (Figure 1, Supplemental Table 3). These patterns demonstrate most males are at a higher risk than their female counterparts.
Role of single nucleotide polymorphisms in population related disease outcomes
Worldwide, the average frequency for the alternate alleles (SNPs) for the ACE2 receptor (in pink) are seen at increased levels in most populations with highest levels in African populations including ASW of African descent and all US populations (Figure 2, Supplemental Table 4). Average means across populations show significant differences for ACE2 SNPs (Welch’s ANOVA p-value < 2.2e-16, df=25, F=596.71, Figure 3).
Benjamini & Hochberg FDR analysis found 70 significant pairs across populations (q- value <0.05). A SNP which increases expression of TMPRSS2, which is believed to cleave the viral S protein into S1 and S2 prior to virus entry into the cells is found at similar levels across the global population (shown in peach, Figure 2, Supplemental Table 4). For all populations the alternate allele was found at a frequency of at least 50% with the country having the highest frequency being Italy with 81.3%. Other populations with greater than 80% frequency for the alternate allele include Peruvians (80.2%), Esan in Nigeria (81.3%) and Southern Han Chinese (81%) (Figure 2, Supplemental Table 4). Chi square analysis across global populations did not find a significant difference in this SNP between males and females for TMPRSS2.
SNPs found across the transcription start site (TSS) in GTEX for ANPEP eQTL cause a decrease in ANPEP expression. ANPEP is believed to be a co-receptor that may assist in SARS-CoV-2 entry into cells. Statistical analysis did not indicate significant differences in prevalence across the global populations for these SNPs. This likely indicates if ANPEP is acting as a co-receptor, no population has increased protection over the others as no population has an increased prevalence for SNPs that would lower ANPEP expression. Chi-square analysis did not find significant differences for these SNPs between males and females across populations. As ANPEP is not significant across populations it is not included in Figure 2.
ENPEP; also believed to be a co-receptor for viral entry into cells does have significant differences across global populations, Welch’s ANOVA (p-value = <.001, df = 25, F=2.93, Figure 4); however, Benjamini & Hochberg FDR analysis indicates no pairs are significant at a q-value < 0.05.There are thirty paired comparisons with q-values of <0.1. We still believe that ENPEP countries with increased frequencies for the alternate alleles may have important consequences as seen in purple and believed to increase ENPEP expression (Figure 2). Countries with these SNPs include Italy and Spain with the highest frequencies followed by the Utah population (European ancestry) in the United States, Great Britain, Finland and Puerto Rico (Figure 2, Supplemental Table 4). Populations from the United States with African and Mexican ancestry also contain ENPEP SNPs as well as African populations (Figure 2, Supplemental Table 4). Additionally, what may be of importance is Asian populations do not contain SNPs for ENPEP (Figure 2, Supplemental Table 4). Chi square analysis did not show a significant difference by sex across populations.