Nephrologists treat hypertension! And not just in our advanced CKD/ESRD patients.
For folks (including fellows in training) who are perhaps more interested in hypertension than the average nephrologist, certification from the American Society of Hypertension (ASH) can offer a greater understanding of hypertension physiology and management (through preparation) as well as a notch in your CV and expertise to advance your career. If you are intrigued, ASH offers some education materials online as well as an explanation of the certification process.
Trainees who have passed their ABIM boards and are enrolled in relevant fellowships (e.g. renal, cards, endo) are able to take the boards. You do not have to pass your nephrology boards first apparently.
If you are interested consider discussing this with your TPD.
Since hypertension is perhaps the most overwhelming area of nephrology, at least in terms of clinical trials, here is a quick cheat sheet of key trials. Not all encompassing but a good start.
Rob Rope, MD Nephrology Fellow, Stanford