Nu Skin Enterprises, Inc. posted first-quarter results with revenue rising 24% to $671.1 million.   “We are pleased to report record first-quarter results, generating year-over-year growth in all five of our regions,” said Truman Hunt, president and chief executive officer. “Our results are particularly encouraging given the business disruption we experienced in China during the first quarter, as well as currency headwinds we faced in many markets. With respect to China, our team took aggressive...