Introduction 29

Both secondary hyperparathyroidism and diabetes mellitus have increased the risk for cardiovascular complication. 30
The prevalence of SHPT among diabetic nephropathy patients is not previously studied. The aim of this study to 31
evaluate the prevalence of SHPT among diabetic nephropathy patients attended to diabetes and nephrology 32
outpatient clinic. 33

Patients and methods: 34

In this retrospective study, 437 diabetic patients were enrolled in this study from 864 diabetic patients who attended 35
diabetes and nephrology outpatient clinics in our tertiary care hospital in Jeddah from Jan 2014 to Feb 2017. 36
Inclusion criteria were: [1] Age ≥18 years, [2] Patient had diabetic nephropathy which was diagnosed based on the 37
presence of urinary albumin/creatinine ratio (uACR) ≥ 30 mg/gm. Exclusion criteria were|: [1] patients were already 38
receiving cinacalcet and/or[2] patients had undergone neck surgery for parathyroidectomy. The intact parathyroid 39
hormone, 25 vitamin D level, uACR results were obtained from patients’ medical records. Patients were divided 40
into two groups: those with euparathyroidism (an iPTH level less than 65 pg/mL) and those with 41
hyperparathyroidism with iPTH level above or equal to 66 pg/mL. 42

Results: 43

Three hundred and seventy-four patients (85.5%) had an iPTH level above normal. We found a significant mean 44
difference between the two groups regarding uACR, eGFR, and serum urea. Our results showed that SHPT group 45

2

had a statistically significant lower level of vitamin D and serum calcium. Furthermore, we found that there was a 46
strong correlation between iPTH level and serum creatinine, eGFR, UACR, vitamin D. 47

Conclusion: 48

SHPT is common among diabetic nephropathy patients. 49

KEYWORDS: 50
SHPT; diabetic nephropathy; vitamin D