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Abstract Diabetes is accompanied by an increased fracture risk. Bone mineral density (BMD) and body mass index (BMI) are positively correlated in type 2 diabetes mellitus (T2DM). Despite normal or higher average BMD, individuals with T2DM have a greater risk of fragility fractures. BMD measurements, which are used for the diagnosis of osteoporosis, underestimate the risk of fracture in diabetes. FRAX underestimates the hip fracture and major osteoporotic fracture risk in diabetic subjects, whereas it performs very well in nondiabetic populations Bone turnover may be assessed using biochemical markers. These markers are generated during the dynamic processes of bone cells, reflecting bone metabolism over a short period of time, and they are better at predicting recent changes. The C-terminal telopeptide of type 1 collagen (CTX) is a degradation product of mature collagen type I. Procollagen type I N-terminal peptide (PINP) is a product of type I collagen formation by osteoblasts. Both have been suggested by the International Osteoporosis Foundation (IOF) as the appropriate bone markers when exploring bone resorption (CTX) and formation (P1NP) in clinical and research settings. Microarchitecture is assessed noninvasively with computed quantitative tomography (QCT) and (MRI). The advantages of using MRI for the image-based assessment of the microarchitecture of trabecular bone are the superior signal-to-noise ratio between bone and bone marrow and the lack of scan radiation. In addition, small dedicated radio frequency coils are used in MRI scanning to enhance image resolution., magnetic resonance techniques allow investigation of both trabecular networks and bone marrow. It was suggested that diffusion tensor imaging (DTI)-derived parameters, mean diffusity (MD), and fractional anisotropy (FA), can specify the nature of the microstructure of bone. Bone marrow fat (BMF) can be measured using Dixon MRI techniques, and it can be distinguished from red marrow. The aim of the study is to assess the ability of diffusion tensor imaging in combination with (BTMs) CTX and P1NP to assess bone quality in T2DM. The study included 88 adult patients with T2DM (premenopausal females and males ≤50 years old); they were divided into 2 groups: 38 diabetic patients already with microvascular complications (group C) and 20 without microvascular complications (group B). In addition, 30 healthy individuals served as the control group (group A). The three groups were matched for age, sex, and BMI. They underwent history taking, general and routine examination, laboratory assessment including CBC, TSH and intact PTH, HBA1C, Calcium, Phosphorus, Creatinine, albumin creatinine ratio and lipid profile, CTX and P1NP. Radiological examination including DXA scan, Dixon MRI and diffusion tensor imaging saggital lumbosacral and coronal both hip. No difference was reported in DXA measurements between the three groups except for the t-score at the (total) femur, which was higher in the diabetic group without microvascular complications than the other two groups. The t-score at the total femur was statistically significantly higher in the diabetic group without microvascular complications than the control group, but not between the diabetic group with microvascular complications and the control group, and there was also no difference between the two diabetic groups. In our study, there was a statistically significant difference in FF by Dixon MRI in the spine but not the hip between the three groups. ADC (spine) and ADC/FF (hip) were statistically significantly higher in the diabetic group with microvascular complications than the control group, but not between the two diabetic groups; there was also no difference between the diabetic group without microvascular complications and the control group. ADC (hip) was statistically significantly higher in the two diabetic groups with and without microvascular complications than the control group, but not between the two diabetic groups, FA (spine), FA (hip), FA/FF (spine), and FA/FF (hip) were statistically significantly lower in the two diabetic groups with and without microvascular complications than the control groups, but not between the two diabetic groups, As regard BTMs, our study showed that PTH level was statistically significantly lower in the diabetic group with microvascular complications than the control group and the diabetic group without microvascular complications but not between the diabetic group without microvascular complications and the control group. The CTX level was statistically significantly lower in the diabetic group without microvascular complications than the control group and also lower in the diabetic group with microvascular complications than the control group, but not between the two diabetic groups. Also, there was no statistically significant difference in P1NP between the three groups; a larger number of cases may be needed as the level of P1NP was lower in the diabetic group with microvascular complications than the other two groups but didn’t reach statistical significance. In our study, PTH correlated with DTI parameters positively with FA spine and FA hip and negatively with ADC spine and ADC/FF hip. Lower PTH levels are strongly associated with the deterioration of trabecular microarchitecture that occurs with diabetes and its associated microvascular complications. Our Study reported that retinopathy and T score AP spine T score total Femur and Z Score Total Femur were negatively correlated with each other. Our study shows that FF at the spine and BMD AP spine, BMD total femur, and BMD forearm re negatively correlated with each other. In our study, a significant positive correlation was found between the CTX level, mean FA spine, FA hip, PTH level, and P1NP. Our study showed that P1NP and CTX levels correlated positively with each other and negatively with HbA1c. Also, P1NP level and mean ADC (spine) negatively correlated with each other. This means that deterioration of the bone microarchitecture and an increase in ADC level are associated with poor glycemic control and lower P1NP. P1NP is correlated negatively with insulin use and positively with FA/FF spine. Both CTX and P1NP are correlated with DTI data, so they perform well for assessing bone quality in patients with diabetes. In our study, a negative correlation between FA at the spine and (ADC hip, ADC spine, ADC/FF spine, ADC/FF hip) was observed. Also, a negative correlation between FA at the hip and (ADC hip, ADC spine, ADC/FF spine, ADC/FF hip) was reported. positive correlations between FA at the spine, FA at the hip, and PTH and CTX levels were observed. That means with the loss of bone organization and decrease in FA, there is a low turnover state (low PTH and CTX levels) that leads to decreased bone remodeling, the accumulation of microcracks, impairment of bone quality, and bone disorganization. a significant negative correlation was shown between ADC spine and PTH level and P1NP. Also, ADC at the hip and PTH level negatively correlated with each other, and ADC at the hip was correlated with the female (higher in female). Conclusion DTI parameters, mean diffusivity (MD) and (FA) of bone marrow water, can provide information about microstructural changes that occur with the development of diabetes. This can explain why, despite normal or higher average BMD, individuals with T2DM have a greater risk of fragility fractures. This technique can define high-risk patients for fragility fractures who have a lower FA and a higher ADC than the defined cut-off value.Diabetes leads to higher BMF and the early aging of bones. Dixon MRI can be used to quantify BMF and assess the fat fraction (FF) in bone marrow. BMF has been identified as a potential marker for diabetes-related skeletal fragility that can be used as a potential therapeutic target for drugs. Restoring proper fat content in the BM of diabetic patients may benefit hematopoiesis, bone strength, and metabolic homeostasis. |