Participants’ Characteristics
The dataset consisted of 309,892 inpatients, of whom 149,834 (48.35%) were female and 160,058 (51.65%) were male. The median age was 63 years (IQR, 56 − 72) and that of males and females was 63 years (IQR, 55 − 71) and 64 years (IQR, 57 − 73), respectively. 21.09% (65,341/309,892) of participants had only one NCD, while 19.49% (60,399/309,892), 16.23% (50,286/309,892) and 13.27% (41,121/309,892) had two, three or four NCDs, respectively. Table 1 shows the proportion of people with DM in different age groups of males and females. The proportion of people with DM in the overall dataset was 22.89%, with a higher proportion among males (23.81%) than females (21.90%). The proportion of people with DM varied by age. The age group of 50 − 59 years and that of 70 − 79 years had the lowest (19.62%) and highest (27.58%) proportion of people with DM, respectively.
Table 1
Prevalence of DM in different age groups of males and females
Age | Female(n/%) | Male(n/%) | P-value |
50~ | 8739(15.82) | 15399(22.73) | < 0.001 |
60~ | 11527(23.66) | 11964(24.43) | < 0.001 |
70~ | 8358(29.16) | 7291(25.99) | < 0.001 |
80~ | 4159(24.17) | 3464(22.69) | < 0.001 |
Table 2 shows the ten most common dyads, triads and quartets NCDs combination associated with DM by sex. The most common NCDs included Hyp, Dys, CVD, CLD, PVD, CHD, CKD, HD, gout, arrhythmia (Arr), anemia (Ane), and prostate disease (PD). Among the dyads NCDs combinations, the three most common combinations in males were (Hyp, DM) (14.17%), (CVD, DM) (7.40%), and (Dys, DM) (7.24%), while these were (Hyp, DM) (14.21%), (Dys, DM) (7.30%), and (CVD, DM) (6.58%) in females. The dyad (CKD, DM) combination was ranked fourth among males and seventh among females. The proportion of people with the dyad {CKD, DM} combination in males is almost 1.5 times higher than that in females. The proportion of males with triad combinations including DM was generally higher than that of females with the same combinations. For example, the proportion of males with the combination {Hyp, CKD, DM} was significantly higher than that of females (4.72% vs 3.44%). However, the proportion of females with the combination (Hyp, Dys, DM) was higher than that of males (5.03% vs 4.59%). In addition, Dys occur 1 time in the male group and 3 times in the female group. The combination {Hyp, CVD, DM} was the most common combination among both sex groups. Among quartets of NCDs combinations, the ten most common combinations were different by sex. The most common quartet combination was (Hyp, Dys, CVD, DM) in females and (Hyp, HD, CHD, DM) in males. The quartet (Hyp, PVD, CVD, DM) combination was the second most common combination in both sexes. All combinations of NCD included Hyp due to its high prevalence.
Table 2
Prevalence of the 10 most common morbidity about DM.
Type | Order | Total | Female | Male |
| Conditions | % | Conditions | % | Conditions | % |
dyads | 1 | Hyp | 14.19 | Hyp | 14.21 | Hyp | 14.17 |
| 2 | Dys | 7.27 | Dys | 7.30 | CD | 7.40 |
| 3 | CD | 7.00 | CD | 6.58 | Dys | 7.24 |
| 4 | CLD | 6.15 | CLD | 5.63 | CKD | 6.78 |
| 5 | PVD | 5.88 | PVD | 5.40 | CLD | 6.64 |
| 6 | CHD | 5.73 | CHD | 5.14 | PVD | 6.33 |
| 7 | CKD | 5.72 | CKD | 4.59 | CHD | 6.29 |
| 8 | HD | 3.80 | HD | 3.29 | PD | 4.53 |
| 9 | gout | 3.35 | gout | 3.03 | HD | 4.27 |
| 10 | Arr | 2.65 | Ane | 2.47 | gout | 3.65 |
triads | 1 | Hyp,CD | 5.55 | Hyp,CD | 5.36 | Hyp,CD | 5.73 |
| 2 | Hyp,Dys | 4.80 | Hyp,Dys | 5.03 | Hyp,CKD | 4.72 |
| 3 | Hyp,CHD | 4.44 | Hyp,CHD | 4.18 | Hyp,CHD | 4.69 |
| 4 | Hyp,PVD | 4.32 | Hyp,PVD | 4.14 | Hyp,Dys | 4.59 |
| 5 | Hyp,CKD | 4.10 | Hyp,CLD | 3.73 | Hyp,PVD | 4.49 |
| 6 | Hyp,CLD | 3.87 | Hyp,CKD | 3.44 | Hyp,CLD | 4.00 |
| 7 | HD,CHD | 3.19 | Dys,CD | 2.81 | HD,CHD | 3.67 |
| 8 | Hyp,HD | 2.98 | Dys,CLD | 2.78 | Hyp,HD | 3.24 |
| 9 | PVD,CD | 2.87 | Hyp,HD | 2.70 | PVD,CD | 3.10 |
| 10 | Dys,CLD | 2.83 | HD,CHD | 2.68 | Hyp,PD | 2.95 |
quartet | 1 | Hyp,HD,CHD | 2.51 | Hyp,Dys,CD | 2.29 | Hyp,HD,CHD | 2.77 |
| 2 | Hyp,PVD,CD | 2.37 | Hyp,PVD,CD | 2.24 | Hyp,PVD,CD | 2.50 |
| 3 | Hyp,Dys,CD | 2.19 | Hyp,HD,CHD | 2.23 | Hyp,Dys,CD | 2.10 |
| 4 | Hyp,PVD,Dys | 1.87 | Hyp,Dys,CLD | 1.88 | Hyp,CKD,CD | 1.91 |
| 5 | Hyp,Dys,CLD | 1.84 | Hyp,PVD,Dys | 1.87 | Hyp,CHD,CD | 1.89 |
| 6 | Hyp,CHD,CD | 1.83 | Hyp,CHD,CD | 1.78 | Hyp,PVD,Dys | 1.87 |
| 7 | Hyp,PVD,CHD | 1.66 | Hyp,Dys,CHD | 1.65 | Hyp,Dys,CLD | 1.80 |
| 8 | Hyp,Dys,CHD | 1.65 | Hyp,PVD,CHD | 1.56 | Hyp,PVD,CHD | 1.76 |
| 9 | Hyp,CKD,CD | 1.64 | Hyp,PVD,CLD | 1.50 | Hyp,CKD,CHD | 1.75 |
| 10 | Hyp,PVD,CLD | 1.58 | Hyp,CLD,CD | 1.47 | Hyp,CKD,PVD | 1.74 |
Note: DM in the table is omitted |
Multimorbidity Patterns In People With Dm
The minimum \(\text{s}\text{u}\text{p}\) was set as 0.005, as a small \(\text{s}\text{u}\text{p}\) would result in \(\text{l}\text{i}\text{f}\text{t}\) with a large random error. When \(\text{l}\text{i}\text{f}\text{t}\) > 1.1, the ARM showed a list of NCDs which were positively related to DM, while \(\text{l}\text{i}\text{f}\text{t}\) < 0.9 created a list of NCDs which were negatively related to DM. The remaining NCDs were weakly related or not related to DM.
After analysis, there were a total of 25 NCDs. Figure 1 and Fig. 2 show the results of the ARM by \(\text{l}\text{i}\text{f}\text{t}\) and \(\text{s}\text{u}\text{p}\), respectively. In Fig. 2, the gray grid indicates \(\text{s}\text{u}\text{p}\) < 0.005.
There were 12 NCDs positively related to DM, including CVD, CHD, Cho, CKD, CLD, HD, Hyp, Dys, gout, PVD, transient cerebral ischemia (Tci), and PD. The proportion of people with most of these NCDs in combination with DM increased with age. Moreover, this proportion increased more in females than in males. The proportion of people with (Dys, DM), (Tci, DM), and (Hyp, DM) was higher in males than that in females. In the group of 50–69 years, the proportion of people with (PVD, DM), (gout, DM), (CLD, DM), (HD, DM), (Cho, DM), (CHD, DM) and (CVD, DM) was higher in males than that in females, with an opposite finding in those aged 70 years and above. The proportion of people with (Tci, DM), (gout, DM) and (Cho, DM) increased slowly with increasing age, while that of (Dys, DM) and (CLD, DM decreased with increasing age in males.
The most common rule was (Hyp, DM). This combination was approximately 1.22 to 1.66-fold more present than expected by chance. The combination (PVD, DM) had the highest \(\text{l}\text{i}\text{f}\text{t}\) in the group of 50 − 59 years. The combination was 2.01 and 1.82-fold more present in females and males, respectively, than would be expected if they were independent. The combinations (Dys, DM) and (gout, DM) had the highest lift value in people of 60 years or older in male and female group, respectively.
Ane, Arr, dizziness/vertigo (Diz), osteoarthropathy (Ost), senile cataract (SC), spondylosis (Spo) were in the weakly related or not related group.
A total of seven NCDs were negatively related to DM, which were bronchiectasis (Bro), chronic gastritis (CG), chronic obstructive pulmonary disease (COPD), disc degeneration (DD), malignant tumor (MT), osteoporosis (OP) and pulmonary heart disease (Pul PHD). In the subgroups of sex and age, DD appeared in the positively related and negatively related groups. The co-occurrence of these NCDs in DM patients were less than a random event.
The NCDs included in this study and related to DM with \(\text{s}\text{u}\text{p}\) < 0.005 were chronic pain, indigestion, chronic cholecystitis, spleen diseases, varicose vein of lower extremity, schizophrenia, bipolar disorder, dementia, Alzheimer’s disease, bronchiectasis, glaucoma, asthma, chronic sinusitis, chronic rhinitis, chronic nasopharyngitis, chronic pharyngitis, chronic laryngitis, diverticulosis of intestine, hypothyroidism, hyperthyroidism, hearing loss, tinnitus, vision impairment or blindness, psoriasis, eczema, migraine, depressed, epilepsy, anxiety, Parkinson’s disease, constipation, chronic tonsillitis, eating disorders, sleep disorders, chronic rheumatic heart disease, heart disease (not specifically), chronic renal failure, chronic gastric ulcer, chronic duodenum ulcer, chronic peptic ulcer, chronic gastrojejunal ulcer, rheumatoid arthritis, obesity, systemic connective tissue disease, edentulous, somatoform disorder, paralysis, urinary incontinence, neurological disorders, and chronic viral hepatitis. To study the relationship between these diseases and DM more samples are needed.
Variations Of Multimorbidity Patterns In People With Dm By Sex And Age
The association rules included a total of nine NCDs, which were CVD, CHD, CKD, CLD, HD, Hyp, Dys, PVD and gout. When looking at different age and sex groups, the types and order of the most common NCDs were quite different in these subgroups. Multimorbidity in patients with DM was more prominent in males and older individuals.
The multimorbidity patterns in people with DM generated by the ARM are presented in Fig. 3. Increased length of the sector indicated a larger \(\text{s}\text{u}\text{p}\). Among the four age groups of males, 48, 81, 137 and 108 rules were detected, while 16, 53, 136 and 115 were found in females. The ten most common rules are shown for each group. The proportion of people with the rules was mostly higher in males than that in females, especially in the group of 50 − 59 years. The most common of all rules was Hyp, followed by Dys and CHD. The prevalence of Hyp was similar in all age and sex groups. Among males, the most common rule which included Dys was (Hyp, Dys, DM) with a large \(\text{s}\text{u}\text{p}\). Among females, Dys and DM were more likely to be associated with other NCDs than that in males and the majority of rules that included Dys appeared in quartets. CHD occurred more frequently in males than in females (sixteen vs. seven) and more frequently in the group of 70 years and older than in the group of 50 − 69 years (seventeen vs. six). In addition, there were four rules that included gout in the female group, while there were none in the male group.
The proportion of people with multimorbidity substantially increased with age, but slightly decreased in the group of 80 years and older. The rules in the groups of younger than 70 years were triads, while most of rules were quartets in the groups of 70 years and older. Hyp, CLD and Dys appeared more frequently in the association rules for the groups of younger than 70 years. The combinations (Hyp, CLD, DM), (Hyp, Dys, DM) and (CLD, Dys, DM) appeared often when ranking the most common combinations by sup in the group of 50 − 59 years. Among those in the group of 70 years and older, the DM multimorbidity network was complex. CKD, CVD, CHD and HD frequent appeared in the association rules.
When exploring the important and strong multimorbidity patterns in people with DM, the threshold for values were set as \(\text{s}\text{u}\text{p}\)=0.01, \(\text{l}\text{i}\text{f}\text{t}\)=1.5, and con was unbounded. If a minimum \(\text{c}\text{o}\text{n}\) threshold was set at 0.8, all rules should have \(\text{l}\text{i}\text{f}\text{t}\) metrics starting at 0.8, which is close to 1 [24].