Adult GH deficiency (AGHD) is associated with reduced bone mineral density, and decreased end-organ sensitivity to the effects of PTH has been suggested as a possible underlying mechanism. We investigated the effects of GH replacement (GHR) on PTH circulating activity and its association with phosphocalcium metabolism and bone turnover in 16 (8 men and 8 women) AGHD patients. Half-hourly blood and 3 hourly urine sampling was performed on each patient over a 24-h period before GHR and then after 1, 3, 6, and 12 months of GHR. GH was commenced at a dose of 0.5 IU/d and was titrated to achieve and maintain an IGF-I SD score within 2 SD of the age-related reference range. The target IGF-I SD score was achieved within 3 months and was maintained at 12 months after GHR in all patients. Our results demonstrated a significant decrease in serum PTH at all visits after GHR compared with baseline values (P < 0.001), with a concomitant increase in nephrogenous cAMP excretion at 1 (P < 0.001) and 3 (P < 0.05) months and increases in serum calcium (P < 0.001), serum phosphate (P < 0.001), 1,25-dihydroxyvitamin D(3) (P < 0.001), type I collagen C-telopeptide (a bone resorption marker; P < 0.001), and procollagen type I amino-terminal propeptide (a bone formation marker; P < 0.001). Simultaneously, we observed a significant decrease in urinary calcium excretion (P < 0.001) and an increase in maximum tubular phosphate reabsorption (P < 0.001). Together these results suggest increased end-organ responsiveness to the effects of circulating PTH resulting in increased bone turnover and reduced calcium excretion. Significant circadian rhythms were observed for serum PTH, phosphate, type I collagen C-telopeptide, and procollagen type I amino-terminal propeptide before and after GHR. However, sustained PTH secretion was observed between 1400-2200 h, with a reduced nocturnal rise in untreated AGHD patients, whereas PTH secretion decreased significantly between 1400-2200 h (P < 0.001), with a significant increase in nocturnal PTH secretion (P < 0.001) after 12 months of GHR. Our results demonstrate that GH may have a regulatory role in bone mineral metabolism, and our data provide a possible underlying mechanism for the development of osteoporosis in AGHD patients. The changes observed after GHR may further explain the beneficial effects of GHR on bone mineral density that have consistently been reported.

Diabetic nephropathy remains a leading cause of end-stage renal disease (ESRD) in western societies, accounting for over one-third of all patients beginning renal replacement therapy. Patients with Type 2 diabetes comprise the largest and fastest-growing single disease group requiring renal support therapy. In addition to the high risk of progression to ESRD, diabetic nephropathy is associated with a very high risk of cardiovascular morbidity and mortality, which is not abolished by dialysis and renal transplantation. While the prognosis of patients with diabetic nephropathy has considerably improved, a greater focus has recently been placed on treating diabetic patients early in order to prevent future organ failure. Microalbuminuria is an important intermediary end-point that correlates strongly with future advanced renal disease and cardiovascular mortality. Recent evidence indicates that optimum glycaemic control, tight blood pressure control, and the regular screening for and early treatment of microalbuminuria are necessary to prevent the development and progression of diabetic renal disease. By utilizing such strategies, the challenge is to reduce the cumulative incidence of overt nephropathy, with its associated increase in cardiovascular mortality, and the requirement for renal support therapy. Over the next 5-10 years, the patient with Type 2 diabetes will need to be the specific focus of such preventive treatment modalities.

Low-dose GHR improves body composition and QoL as early as 1 month after commencement and the beneficial effects continue at 3 months. Most importantly, these changes occur in the absence of side-effects. We therefore suggest the use of low-dose GH therapy, maintaining IGF-I between the median and upper end of the age-related reference range, for the treatment of AGHD.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has resulted in a considerable amount of morbidity and mortality worldwide since December 2019. Patients with coronavirus disease (COVID-19) most commonly present with respiratory manifestations, while cardiac manifestations were reported as a complication and seldom as a presenting feature. We report two cases of new-onset atrial fibrillation occurring in middle-aged men with no significant past medical history. The first patient presented with symptomatic atrial fibrillation; however, during his hospitalization course, he developed a fever, which led to the diagnosis of infection with SARS-CoV-2. The second patient presented from urgent care after being diagnosed with COVID-19 associated with newly diagnosed atrial fibrillation. Both patients were treated symptomatically for COVID-19 and discharged home after reverting to sinus rhythm. Physicians should be aware of the variable clinical presentations of COVID-19, especially in new or worsening cardiac illnesses, in order to practice the appropriate personal protection practices. More studies are needed to identify the viral mechanisms leading to the dysregulation of cardiac rhythm.

Diabetic nephropathy remains a leading cause of endstage renal disease (ESRD) in western societies, accounting for about 40% of all patients beginning renal replacement therapy. Patients with type 2 diabetes comprise the largest and fastest growing single disease group requiring renal replacement therapy. In addition to the high risk of progression to ESRD, diabetic nephropathy is associated with a very high risk of cardiovascular (CV) morbidity and mortality, which is not abolished by dialysis or renal transplantation. Over the past two decades there have been major advances in our attempts to understand the risk factors for development and progression of diabetic renal dysfunction, that have resulted in better characterisation of the natural history of this serious complication. Effective antihypertensive treatment and aggressive management of CV risk factors have helped improve the prognosis of patients with overt diabetic nephropathy, particularly those with type 1 diabetes. However, for the larger proportion of patients with type 2 diabetes, the renal and CV prognoses are still poor. Recently, more focus has been placed on treating diabetic patients early in order to prevent future organ damage. Microalbuminuria is an