Summary Demographic Table

Table 1 . summary Distribution of all variables

label levels all
Age Mean (SD) 47.2 (10.1)
Sex FEMALE 62 (62.0)
MALE 38 (38.0)
Smoking Non-Smoker 80 (80.0)
Smoker 20 (20.0)
SBP Mean (SD) 145.0 (15.2)
DBP Mean (SD) 88.4 (9.3)
FBS Mean (SD) 148.8 (26.6)
PPBS Mean (SD) 176.0 (33.5)
HBA1C Mean (SD) 7.4 (0.7)
ABPI Mean (SD) 1.0 (0.1)
ASCVD Mean (SD) 7.8 (2.5)
CRP Mean (SD) 6.8 (3.6)
HDL Mean (SD) 32.4 (6.8)
LDL Mean (SD) 152.0 (29.7)
TG Mean (SD) 202.0 (40.9)
Total_Cholesterol Mean (SD) 224.8 (31.9)
Urea Mean (SD) 40.0 (11.3)
Creatinine Mean (SD) 1.2 (0.2)
PAD NOT PAD 67 (67.0)
PAD 33 (33.0)

Table 2 . summary Distribution of all variables ,Groupwise(Case vs Control )

label levels cases control p
Age Mean (SD) 47.0 (10.4) 47.8 (9.0) 0.566
Sex FEMALE 50 (62.5) 12 (60.0) 0.837
MALE 30 (37.5) 8 (40.0)
Smoking Non-Smoker 65 (81.2) 15 (75.0) 0.532
Smoker 15 (18.8) 5 (25.0)
SBP Mean (SD) 150.1 (11.6) 124.6 (10.0) <0.001
DBP Mean (SD) 92.0 (6.0) 74.0 (5.0) <0.001
FBS Mean (SD) 160.0 (15.0) 104.0 (9.9) <0.001
PPBS Mean (SD) 190.0 (20.0) 119.9 (5.9) <0.001
HBA1C Mean (SD) 7.7 (0.3) 6.0 (0.2) <0.001
abpi Mean (SD) 0.9 (0.1) 1.1 (0.1) <0.001
ascvd Mean (SD) 9.0 (1.0) 3.2 (0.2) <0.001
crp Mean (SD) 8.0 (3.0) 2.1 (0.7) <0.001
HDL Mean (SD) 30.0 (5.0) 42.0 (4.1) <0.001
LDL Mean (SD) 165.0 (15.0) 100.0 (9.9) <0.001
TG Mean (SD) 220.0 (20.1) 129.9 (15.0) <0.001
Total_Cholesterol Mean (SD) 239.0 (15.2) 168.1 (10.8) <0.001
Urea Mean (SD) 45.1 (5.0) 19.9 (5.0) <0.001
Creatinine Mean (SD) 1.3 (0.1) 0.9 (0.1) <0.001
PAD NOT PAD 48 (60.0) 19 (95.0) 0.003
PAD 32 (40.0) 1 (5.0)

Table 3 . summary Distribution of all variables ,Groupwise(PAD vs Non PAD )

label levels NOT PAD PAD p
Age Mean (SD) 47.7 (10.1) 46.1 (10.2) 0.220
Sex FEMALE 41 (61.2) 21 (63.6) 0.813
MALE 26 (38.8) 12 (36.4)
Smoking Non-Smoker 56 (83.6) 24 (72.7) 0.202
Smoker 11 (16.4) 9 (27.3)
Group cases 48 (71.6) 32 (97.0) 0.003
control 19 (28.4) 1 (3.0)
SBP Mean (SD) 144.2 (16.4) 146.4 (12.5) 0.805
DBP Mean (SD) 87.4 (10.3) 90.4 (6.4) 0.285
FBS Mean (SD) 144.6 (29.1) 157.4 (18.0) 0.081
PPBS Mean (SD) 170.1 (36.1) 187.9 (23.6) 0.056
HBA1C Mean (SD) 7.2 (0.8) 7.6 (0.4) 0.140
ABPI Mean (SD) 1.0 (0.1) 0.8 (0.1) <0.001
ASCVD Mean (SD) 7.5 (2.8) 8.5 (1.4) 0.548
CRP Mean (SD) 6.8 (3.6) 6.8 (3.5) 0.702
HDL Mean (SD) 33.4 (7.4) 30.4 (5.1) 0.055
LDL Mean (SD) 147.0 (32.9) 162.1 (18.2) 0.113
TG Mean (SD) 195.7 (45.8) 214.8 (24.4) 0.196
Total_Cholesterol Mean (SD) 219.6 (35.8) 235.4 (18.6) 0.172
Urea Mean (SD) 37.5 (12.0) 45.2 (7.2) 0.002
Creatinine Mean (SD) 1.2 (0.2) 1.3 (0.1) 0.076

Demographic Variables

Distribution of Demographic Variables in Our Population

Age

Fig.1 Plot of Age distribution across Groups

The Dodged bar chart above represents individual counts representing frequency of age_grp categories 40-50,30-40,50-60,60-70,20-30 and 80-90 in categories cases and control . Subgroup 40-50 has highest percentage 26/80 ( 32.5 % ) in Diabetic group . Subgroup 50-60 has highest percentage 11/20 ( 55 % ) in Control group . To formally check for association between groups we performed pearson chi-square test .

we found a Non-significant association between age_grp and Group(Cases and Control) . The chi-square statistic was 7.38 . The degree of freedom was 5 and P value was 0.19 .Contingency and Proportion table are shown below

Table 4

Group age_grp n value 95 % Confidence Interval
cases 20-30 2 2/80 ( 2.5 %) 0.52% - 7.78%
cases 30-40 21 21/80 ( 26.25 %) 17.57% - 36.61%
cases 40-50 26 26/80 ( 32.5 %) 23% - 43.24%
cases 50-60 22 22/80 ( 27.5 %) 18.64% - 37.96%
cases 60-70 8 8/80 ( 10 %) 4.84% - 17.98%
cases 80-90 1 1/80 ( 1.25 %) 0.14% - 5.69%
control 20-30 1 1/20 ( 5 %) 0.54% - 21.08%
control 30-40 3 3/20 ( 15 %) 4.41% - 34.86%
control 40-50 5 5/20 ( 25 %) 10.24% - 46.42%
control 50-60 11 11/20 ( 55 %) 33.77% - 74.9%

Table 5

cases control
20-30 2 1
30-40 21 3
40-50 26 5
50-60 22 11
60-70 8 0
80-90 1 0

Gender

Figure 2 Sex Distribution in Our Population

The Dodged bar chart above represents individual counts representing frequency of Sex categories MALE and FEMALE in categories cases and control belonging to group Group. Subgroup FEMALE has highest percentage 50/80 ( 62.5 % ) in group cases . Subgroup FEMALE has highest percentage 12/20 ( 60 % ) in group control . To formally check for association between groups we performed pearson chi-square test .

we found a Non-significant association between Sex and Group. The chi-square statistic was 0 . The degree of freedom was 1 and P value was 1 .Contingency and Proportion table are shown below

Table 6

Group Sex n value 95 % Confidence Interval
cases FEMALE 50 50/80 ( 62.5 %) 51.6% - 72.51%
cases MALE 30 30/80 ( 37.5 %) 27.49% - 48.4%
control FEMALE 12 12/20 ( 60 %) 38.39% - 78.94%
control MALE 8 8/20 ( 40 %) 21.06% - 61.61%

Table 7

cases control
FEMALE 50 12
MALE 30 8

Smoker

Figure 3 Distribution Of smokers in Our Population

The Dodged bar chart above represents individual counts representing frequency of Smoking categories Smoker and Non-Smoker in categories cases and control . Subgroup Non-Smoker has highest percentage 65/80 ( 81.25 % ) in group cases . Subgroup Non-Smoker has highest percentage 15/20 ( 75 % ) in group control . To formally check for association between groups we performed pearson chi-square test .

we found a Non-significant association between Smoking and Group. The chi-square statistic was 0.1 . The degree of freedom was 1 and P value was 0.75 .Contingency and Proportion table are shown below

Table 8

Group Smoking n value 95 % Confidence Interval
cases Non-Smoker 65 65/80 ( 81.25 %) 71.67% - 88.61%
cases Smoker 15 15/80 ( 18.75 %) 11.39% - 28.33%
control Non-Smoker 15 15/20 ( 75 %) 53.58% - 89.76%
control Smoker 5 5/20 ( 25 %) 10.24% - 46.42%

Table 9

cases control
Non-Smoker 65 15
Smoker 15 5

Figure 3A Distribution Of PAD in Our Population

The Dodged bar chart above represents individual counts representing frequency of PAD categories PAD and NOT PAD in categories cases and control. Subgroup NOT PAD has highest percentage 48/80 ( 60 % ) in group cases . Subgroup NOT PAD has highest percentage 19/20 ( 95 % ) in group control . To formally check for association between groups we performed pearson chi-square test .

we found a Significant association between PAD and Group. The chi-square statistic was 7.35 . The degree of freedom was 1 and P value was 0.01 .Contingency and Proportion table are shown below

Table 8A

Group PAD n value 95 % Confidence Interval
cases NOT PAD 48 48/80 ( 60 %) 49.07% - 70.22%
cases PAD 32 32/80 ( 40 %) 29.78% - 50.93%
control NOT PAD 19 19/20 ( 95 %) 78.92% - 99.46%
control PAD 1 1/20 ( 5 %) 0.54% - 21.08%

Table 9A

cases control
NOT PAD 48 19
PAD 32 1

Outcomes Of Interest

ABPI

Figure 4 Boxplot Of Distribution Of ABPI in our Population

In this Figure we see Box plot of ABPI in : cases and control respectively .The individual jittered data points of ABPI are overlaid over transparent Boxplot for better visualisation. We see distribution of data in individual sub-groups based on these box-plots. The lower edge of box plot represents -first quartile (Q1), Horizontal bar represents the median, Upper edge represnts third quartile (Q3), Two black lines (whiskers) emanating from box-plots signify range of non-outlier data for the particular sub-group. Lower whisker represents minimum(Q1- 1.5 interquartile range) non-outlier limit of ABPI and upper whisker represnts maximum(Q1+1.5interquartile range) of ABPI .Any data beyond whiskers of box-plots represents outliers in the sub-groups The big brown point in the box-plots represents mean ABPI of 2 groups and it has been annotated in the figure itself Summary Statistics of the groups is presented in table below

Table 10 Summary Table Of ABPI within Groups

Group n Mean SD Median Minimum Maximum
cases 80 0.922 0.093 0.920 0.69 1.14
control 20 1.131 0.095 1.135 0.89 1.32

The mean in Group cases [ 0.92 ± 0.09 ] was significantly lower than Group control [ 1.13 ± 0.09 ] . The mean difference was -0.21 and 95 % confidence interval of the difference was ( -0.26 - -0.16 ) . The p value was <0.001 . The t statistic was -8.88 and degree of freedom of the Welch unpaired two-sample t test was 28.84 .In Formal statistical notation this result is expressed as : t(28.84) = -8.88, p= <0.001.. The detailed statistical parameters of T test are given in table below.

TABLE 11

variable group1 group2 statistic df p
ABPI cases control -8.88 28.84 <0.001

Figure 5 Barplot Of Age-Sex Distribution Of ABPI in our Population

Table 12 Age-Sex Distribution Of ABPI in our Population

Group age_grp Sex n Mean ( ABPI ) SD ( ABPI ) Median ( ABPI )
cases 20-30 FEMALE 1 0.99 0.99
cases 20-30 MALE 1 0.90 0.90
cases 30-40 FEMALE 14 0.92 0.13 0.92
cases 30-40 MALE 7 0.91 0.08 0.91
cases 40-50 FEMALE 12 0.89 0.08 0.88
cases 40-50 MALE 14 0.89 0.07 0.88
cases 50-60 FEMALE 17 0.95 0.1 0.94
cases 50-60 MALE 5 0.94 0.07 0.93
cases 60-70 FEMALE 5 0.93 0.08 0.96
cases 60-70 MALE 3 1.03 0.04 1.04
cases 80-90 FEMALE 1 0.85 0.85
control 20-30 FEMALE 1 1.13 1.13
control 30-40 FEMALE 1 1.15 1.15
control 30-40 MALE 2 1.12 0.12 1.12
control 40-50 FEMALE 3 1.06 0.16 1.08
control 40-50 MALE 2 1.17 0.04 1.17
control 50-60 FEMALE 7 1.17 0.09 1.14
control 50-60 MALE 4 1.10 0.09 1.07

CRP

Figure 6 Boxplot Of Distribution Of CRP in our Population

In this Figure we see Box plot of CRP in 2 sub-groups : cases and control respectively .The individual jittered data points of CRP are overlaid over transparent Boxplot for better visualisation. We see distribution of data in individual sub-groups of Group based on these box-plots. The lower edge of box plot represents -first quartile (Q1), Horizontal bar represents the median, Upper edge represnts third quartile (Q3), Two black lines (whiskers) emanating from box-plots signify range of non-outlier data for the particular sub-group. Lower whisker represents minimum(Q1- 1.5 interquartile range) non-outlier limit of CRP and upper whisker represnts maximum(Q1+1.5interquartile range) of CRP .Any data beyond whiskers of box-plots represents outliers in the sub-groups The big brown point in the box-plots represents mean CRP of 2 groups and it has been annotated in the figure itself We can see the statistical summary of Test while summary statistics of Effect size and its confidence Interval (represented as Hedges’s G ) at top of plot. Summary Statistics of the groups is presented in table below

Table 13 Summary Table Of CRP within Groups

Group n Mean SD Median Minimum Maximum
cases 80 8.000 3.001 7.925 1.80 16.15
control 20 2.099 0.699 1.965 1.07 3.53

The mean in Group cases [ 8 ± 3.0 ] was significantly higher than Group control [ 2.1 ± 0.7 ] . The mean difference was 5.9 and 95 % confidence interval of the difference was ( 5.17 - 6.64 ) . The p value was <0.001 . The t statistic was 15.94 and degree of freedom of the Welch unpaired two-sample t test was 97.85 .In Formal statistical notation this result is expressed as : t(97.85) = 15.94, p= <0.001.

TABLE 14

variable group1 group2 statistic df p
CRP cases control 15.94 97.85 <0.001

Figure 5 Barplot Of Age-Sex Distribution Of CRP in our Population

Table 15 Age-Sex Distribution Of CRP in our Population

Group age_grp Sex n Mean ( CRP ) SD ( CRP ) Median ( CRP )
cases 20-30 FEMALE 1 12.40 12.40
cases 20-30 MALE 1 5.30 5.30
cases 30-40 FEMALE 14 7.74 3.5 6.76
cases 30-40 MALE 7 8.64 2.19 9.76
cases 40-50 FEMALE 12 7.62 3.18 7.89
cases 40-50 MALE 14 8.17 3.28 8.73
cases 50-60 FEMALE 17 8.22 3.39 7.45
cases 50-60 MALE 5 6.45 1.44 7.24
cases 60-70 FEMALE 5 8.93 2.52 9.48
cases 60-70 MALE 3 8.13 1.34 8.20
cases 80-90 FEMALE 1 6.60 6.60
control 20-30 FEMALE 1 2.04 2.04
control 30-40 FEMALE 1 1.98 1.98
control 30-40 MALE 2 2.74 1.12 2.74
control 40-50 FEMALE 3 1.96 1.08 1.64
control 40-50 MALE 2 2.37 0.14 2.37
control 50-60 FEMALE 7 2.20 0.75 2.24
control 50-60 MALE 4 1.62 0.28 1.60

Selected Correlations

ABPI and CRP

Figure showing Correlation between ABPI and CRP

The scatter plots above show relationship between CRP on X axis and ABPI on Y axis. Graphically, we see that as CRP increases, ABPI decreases . On a formal statistical linear regression analysis, we that line of best fit (blue line signifying line with least square difference) also has a negative slope implying a negative correlation. The gray shaded error around blue line signifies 95% confidence interval of linear regression line of best fit. The correlation between two variables is Significant . The Pearson’s correlation between CRP and ABPI is -0.26 with 95% Confidence Interval of -0.43 to -0.07. the t statistic is -2.65 The p value is 0.01 .The degree of freedom is 98. In formal statistical notation this expressed as t(98)= -2.65, P= 0.01. r(Pearson) = -0.26 95% C.I. [-0.43–0.07]. n= 100. The correlation is summmarised in table below

Table 16. Table Summarizing correlation between CRP and ABPI

Group 1 Group 2 Degree of Freedom T statistic Correlation 95 % C.I. P value
CRP ABPI 98 -2.65 -0.26 -0.43–0.07 0.01

Table 16 Table with summary statistics of CRP and ABPI

variable n Mean SD Median Minimum Maximum
ABPI 100 0.964 0.125 0.945 0.69 1.32
CRP 100 6.820 3.592 6.915 1.07 16.15

ABPI and HBA1c**

Figure showing Correlation between ABPI and HBA1C

he scatter plots above show relationship between HBA1C on X axis and ABPI on Y axis. Graphically, we see that as HBA1C increases, ABPI decreases . On a formal statistical linear regression analysis, we that line of best fit (blue line signifying line with least square difference) also has a negative slope implying a negative correlation. The gray shaded error around blue line signifies 95% confidence interval of linear regression line of best fit. The correlation between two variables is Significant . The Pearson’s correlation between HBA1C and ABPI is -0.56 with 95% Confidence Interval of -0.68 to -0.41. the t statistic is -6.77 The p value is <0.001 .The degree of freedom is 98. In formal statistical notation this expressed as t(98)= -6.77, P= <0.001. r(Pearson) = -0.56 95% C.I. [-0.68–0.41]. n= 100. The correlation is summmarised in table below

Table 17. Table Summarizing correlation between ABPI and HBA1c

Group 1 Group 2 Degree of Freedom T statistic Correlation 95 % C.I. P value
HBA1C ABPI 98 -6.77 -0.56 -0.68–0.41 <0.001

Table 18 Table with summary statistics of ABPI and HBA1C

variable n Mean SD Median Minimum Maximum
ABPI 100 0.964 0.125 0.945 0.690 1.320
HBA1C 100 7.360 0.739 7.628 5.625 8.577

ABPI AND LDL

Figure showing Correlation between ABPI and LDL

The scatter plots above show relationship between LDL on X axis and ABPI on Y axis. Graphically, we see that as LDL increases, ABPI decreases . On a formal statistical linear regression analysis, we that line of best fit (blue line signifying line with least square difference) also has a negative slope implying a negative correlation. The gray shaded error around blue line signifies 95% confidence interval of linear regression line of best fit. The correlation between two variables is Significant . The Pearson’s correlation between LDL and ABPI is -0.54 with 95% Confidence Interval of -0.67 to -0.39. the t statistic is -6.38 The p value is <0.001 .The degree of freedom is 98. In formal statistical notation this expressed as t(98)= -6.38, P= <0.001. r(Pearson) = -0.54 95% C.I. [-0.67–0.39]. n= 100. The correlation is summmarised in table below

Table 19. Table Summarizing correlation between ABPI and LDL

Group 1 Group 2 Degree of Freedom T statistic Correlation 95 % C.I. P value
ABPI LDL 98 -6.38 -0.54 -0.67–0.39 <0.001

Table 20 Table with summary statistics of ABPI and LDL

variable n Mean SD Median Minimum Maximum
ABPI 100 0.964 0.125 0.945 0.69 1.32
LDL 100 152.000 29.671 162.000 77.00 199.00

ABPI and 10 yr ASCVD Risk Score

Figure showing Correlation between ABPI and ASCVD

The scatter plots above show relationship between ASCVD on X axis and ABPI on Y axis. Graphically, we see that as ASCVD increases, ABPI decreases . On a formal statistical linear regression analysis, we that line of best fit (blue line signifying line with least square difference) also has a negative slope implying a negative correlation. The gray shaded error around blue line signifies 95% confidence interval of linear regression line of best fit. The correlation between two variables is Significant . The Pearson’s correlation between ASCVD and ABPI is -0.55 with 95% Confidence Interval of -0.68 to -0.4. the t statistic is -6.58 The p value is <0.001 .The degree of freedom is 98. In formal statistical notation this expressed as t(98)= -6.58, P= <0.001. r(Pearson) = -0.55 95% C.I. [-0.68–0.4]. n= 100. The correlation is summmarised in table below

Table 21. Table Summarizing correlation between ABPI and ASCVD

Group 1 Group 2 Degree of Freedom T statistic Correlation 95 % C.I. P value
ABPI ASCVD 98 -6.58 -0.55 -0.68–0.4 <0.001

Table 22 Table with summary statistics of ASCVD and ABPI

variable n Mean SD Median Minimum Maximum
ABPI 100 0.964 0.125 0.945 0.69 1.32
ASCVD 100 7.840 2.498 8.660 2.78 11.75

Correlation Matrix Of selected Variables

Table 23 Correlation table of Selected variables TSH,LDL,T3,T4,TC,HDL,LDL,TG,LipoproteinA,ASCVD,HbA1c with their confidence intervals

Variable1 Variable2 Correlation pvalue significance Confidence_Interval
LDL Total_Cholesterol 0.99 <0.001 Significant 0.98-0.99
TG HBA1C 0.93 <0.001 Significant 0.89-0.95
LDL HBA1C 0.92 <0.001 Significant 0.89-0.95
TG Total_Cholesterol 0.92 <0.001 Significant 0.88-0.95
Total_Cholesterol HBA1C 0.92 <0.001 Significant 0.88-0.94
LDL TG 0.90 <0.001 Significant 0.85-0.93
ASCVD HBA1C 0.87 <0.001 Significant 0.81-0.91
SBP DBP 0.86 <0.001 Significant 0.8-0.9
ASCVD Total_Cholesterol 0.84 <0.001 Significant 0.77-0.89
ASCVD TG 0.84 <0.001 Significant 0.76-0.89
ASCVD LDL 0.83 <0.001 Significant 0.76-0.88
HDL HBA1C -0.83 <0.001 Significant -0.88–0.75
LDL HDL -0.79 <0.001 Significant -0.86–0.71
HDL TG -0.79 <0.001 Significant -0.85–0.7
DBP HBA1C 0.78 <0.001 Significant 0.69-0.85
DBP LDL 0.76 <0.001 Significant 0.66-0.83
DBP Total_Cholesterol 0.76 <0.001 Significant 0.66-0.83
DBP TG 0.74 <0.001 Significant 0.63-0.81
HDL Total_Cholesterol -0.72 <0.001 Significant -0.81–0.61
ASCVD DBP 0.70 <0.001 Significant 0.58-0.79
ASCVD HDL -0.67 <0.001 Significant -0.77–0.55
SBP HBA1C 0.67 <0.001 Significant 0.54-0.76
CRP Total_Cholesterol 0.65 <0.001 Significant 0.52-0.75
CRP LDL 0.65 <0.001 Significant 0.51-0.75
CRP ASCVD 0.64 <0.001 Significant 0.51-0.74
CRP HBA1C 0.64 <0.001 Significant 0.5-0.74
DBP HDL -0.63 <0.001 Significant -0.74–0.5
SBP Total_Cholesterol 0.61 <0.001 Significant 0.47-0.72
SBP LDL 0.61 <0.001 Significant 0.47-0.72
SBP TG 0.61 <0.001 Significant 0.47-0.72
CRP TG 0.61 <0.001 Significant 0.47-0.72
ASCVD SBP 0.59 <0.001 Significant 0.45-0.71
CRP DBP 0.57 <0.001 Significant 0.42-0.69
ABPI HBA1C -0.56 <0.001 Significant -0.68–0.41
ABPI ASCVD -0.55 <0.001 Significant -0.68–0.4
ABPI Total_Cholesterol -0.55 <0.001 Significant -0.67–0.39
ABPI LDL -0.54 <0.001 Significant -0.67–0.39
CRP SBP 0.53 <0.001 Significant 0.37-0.66
SBP HDL -0.51 <0.001 Significant -0.65–0.35
ABPI TG -0.50 <0.001 Significant -0.63–0.34
CRP HDL -0.50 <0.001 Significant -0.63–0.33
ABPI DBP -0.46 <0.001 Significant -0.61–0.3
ABPI SBP -0.41 <0.001 Significant -0.56–0.23
ABPI HDL 0.39 <0.001 Significant 0.21-0.55
ABPI CRP -0.26 0.00945 Significant -0.43–0.07

Linear regression model

Multiple linear regression was conducted to find best combination of HBA1C,Age,SexMALE,LDL,TG & CRP for predicting ABPI . Dummy indicator(0/1) were used for categorical variables. The Forest plot above shows standardized regression coefficients of HBA1C,Age,SexMALE,LDL,TG & CRP with their confidence intervals as horizontal error bars on X axis. An error bar which crosses vertical line of zero in this plot is non-significant.

We fitted a linear model (estimated using OLS) to predict ABPI with HBA1C, Age, Sex, LDL, TG and CRP (formula = ABPI ~ HBA1C + Age + Sex + LDL + TG + CRP). Standardized parameters were obtained by fitting the model on a standardized version of the dataset. Effect sizes were labelled following Funder's (2019) recommendations.



The model explains a significant and substantial proportion of variance (R2 = 0.36, F(6, 93) = 8.86, p < .001, adj. R2 = 0.32). The model's intercept, corresponding to ABPI = 0, HBA1C = 0, Age = 0, Sex = , LDL = 0, TG = 0 and CRP = 0, is at 1.66 (SE = 0.19, 95% CI [1.29, 2.03[, std. intercept = 0.02, p < .001). Within this model:

  - The effect of HBA1C is negative and can be considered as medium and significant (beta = -0.10, SE = 0.04, 95% CI [-0.19, -0.01[, std. beta = -0.60, p < .05).
  - The effect of Age is positive and can be considered as very small and not significant (beta = 0.00, SE = 0.00, 95% CI [0.00, 0.00[, std. beta = 0.12, p > .1).
  - The effect of Sex (MALE) is negative and can be considered as tiny and not significant (beta = -0.01, SE = 0.02, 95% CI [-0.05, 0.04[, std. beta = -0.05, p > .1).
  - The effect of LDL is negative and can be considered as small and not significant (beta = 0.00, SE = 0.00, 95% CI [0.00, 0.00[, std. beta = -0.29, p > .1).
  - The effect of TG is positive and can be considered as very small and not significant (beta = 0.00, SE = 0.00, 95% CI [0.00, 0.00[, std. beta = 0.19, p > .1).
  - The effect of CRP is positive and can be considered as very small and not significant (beta = 0.01, SE = 0.00, 95% CI [0.00, 0.01[, std. beta = 0.20, p = 0.08).

Table 24. Regression Table

Parameter Coefficient CI_low CI_high p Std_Coefficient Fit
(Intercept) 1.662 1.292 2.033 0 0.018
HBA1C -0.101 -0.19 -0.012 0.026 -0.598
Age 0.002 -0.001 0.004 0.143 0.123
SexMALE -0.006 -0.048 0.037 0.787 -0.046
LDL -0.001 -0.003 0.001 0.213 -0.288
TG 0.001 -0.001 0.002 0.416 0.187
CRP 0.007 -0.001 0.014 0.075 0.197
R2 0.364
R2 (adj.) 0.323

The combination of these predictors significantly predicted ABPI .There were 100 observations in our model. The number of predictors in model was 6 ,while degree of freedom of residuals(no.of observation-number Of predictors in model) was 93. In statistical notation this is expressed as F(6,93) = 8.86, P = <0.001 .The standard deviation of residual error was 0.1 implying ABPI was predicted with average accuracy of +- 0.1 by our model. The adjusted R - Square for our model is 0.32 implying our model predicts 32.27 percentage variation in ABPI .

In Our Multivariable linear regression Model,On adjusting for all variables , HBA1C significantly predicted ABPI .

Our Final regression equation was predicted ABPI = 1.6 -0.1HBA1C +0.002Age -0.006SexMALE -0.001LDL +0.0001TG +0.0007CRP

Interpretation

1 unit change in HBA1C leads to 0.1 decrease in ABPI . Rest of values are not Significant.

Table 25 Univariable and Multivariable Regression coefficients

Dependent: ABPI Mean (sd) Coefficient (univariable) Coefficient (multivariable)
HBA1C [5.62,8.58] 1.0 (0.1) -0.096 (-0.124 to -0.068, p<0.0001) -0.101 (-0.190 to -0.012, p=0.0263)
Age [27,82] 1.0 (0.1) 0.001 (-0.001 to 0.004, p=0.2469) 0.002 (-0.001 to 0.004, p=0.1429)
Sex FEMALE 1.0 (0.1)
MALE 1.0 (0.1) -0.003 (-0.055 to 0.048, p=0.8965) -0.006 (-0.048 to 0.037, p=0.7872)
LDL [77,199] 1.0 (0.1) -0.002 (-0.003 to -0.002, p<0.0001) -0.001 (-0.003 to 0.001, p=0.2130)
TG [101,264] 1.0 (0.1) -0.002 (-0.002 to -0.001, p<0.0001) 0.001 (-0.001 to 0.002, p=0.4163)
CRP [1.07,16.1] 1.0 (0.1) -0.009 (-0.016 to -0.002, p=0.0095) 0.007 (-0.001 to 0.014, p=0.0754)